Geographic Concentration [Member] Geographic Concentration Risk [Member] Business Acquisition [Axis] Business Acquisition [Axis] Undistributed earnings allocated to common stockholders Undistributed Earnings Allocated To Common Stockholders The earnings that is allocated to common stock to the extend that each stockholder may share in the earnings as if all the earnings for the period has been distributed. Restatement [Axis] Revision of Prior Period [Axis] Non-U.S., Current Current Foreign Tax Expense (Benefit) Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Number of existing legal claims or proceedings that are likely to have a material effect on the Company's business Loss Contingency, Pending Claims, Number Finance lease payments due in 2024 Finance Lease, Liability, Payments, Due in Rolling Year Two Deferred Income Taxes Deferred Income Tax Assets, Net Finance Lease, Right-of-Use Asset Finance Lease, Right-of-Use Asset, after Accumulated Amortization Exercise Price $244 [Member] Price Range One [Member] Exercise Price Range of $244-276 Repayments of borrowings RepaymentsOfLongTermDebtAndDebtExtinguishmentCosts The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer and for cost from early extinguishment of debt, which includes only the premium paid. Advance Related To Kaplan University Transaction Advance Related To Kaplan University Transaction Advance related to Kaplan University Transaction. State and Local, Total State and Local Income Tax Expense (Benefit), Continuing Operations Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Vesting Condition [Domain] Vesting Condition [Domain] Vesting Condition [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Finance Lease, Liability Total finance lease liability Finance Lease, Liability Property, plant and equipment, gross Property, Plant and Equipment, Gross Fair value of debt instrument Debt Instrument, Fair Value Disclosure Capital Expenditures Property, Plant and Equipment, Additions Investment Manager 2 [Member] Investment Manager 2 [Member] Investment Manager 2 [Member] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Investments Investment [Text Block] Capital in excess of par value Additional Paid in Capital Benefits paid, net of Medicare subsidy Defined Benefit Plan Benefits Paid Net The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets. This amount is net of Medicary subsidies. Applicable interest rate margin Debt Instrument, Basis Spread on Variable Rate Aggregate purchase price, net of cash acquired Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest, Net Of Cash Received Amount recognized as of the acquisition date for the assets, including goodwill, in excess of (less than) the aggregate liabilities assumed, less the noncontrolling interest in the acquiree, net of cash received. Schedule of Future Minimum Rental Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Depreciation of property, plant and equipment Depreciation Exercised, Number of Shares Exercised, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Schedule of Indefinite-Lived Intangible Assets [Table] Schedule of Indefinite-Lived Intangible Assets [Table] Through 2027 [Member] Loss Carryforwards Expirations Range One [Member] -- None. No documentation exists for this element. -- March 22, 2018 through June 30, 2023 [Member] March 22, 2018 through June 30, 2023 [Member] Period of time March 22, 2018 through June 30, 2023 for which the TOSA term applies (first 5 years) Operating lease, weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Interest rate Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Translation adjustments arising during the year Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability Add: Additional undistributed earnings due to dilutive stock options Additional Undistributed Earnings Due To Dilutive Stock Options The earnings that is allocated to common stock due to the dilutive effect of stock options in diluted earnings per share. Pension credit per employee Pension Credit Retention Program, Credit Per Employee, Amount The amount of pension credit per employee in the pension credit retention program. Options outstanding exercisable in 2023 (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year One Options outstanding exercisable in year one. Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Contract costs capitalized during the period Contract Costs Capitalized During the Period Capitalized contract costs associated with new contracts entered into during the period. State and Local, Current Current State and Local Tax Expense (Benefit) Acquisition of noncontrolling interest Noncontrolling Interest, Increase from Business Combination Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Settlement Defined Benefit Plan, Plan Assets, Payment for Settlement Shares excluded from earnings per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Senior Manager [Member] Senior Manager [Member] Senior Manager Transition and Operations Support Agreement Renewal Periods Transition and Operations Support Agreement Renewal Periods Transition and Operations Support Agreement Renewal Periods after initial 30 year term Operating lease payments due thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Equity Component [Domain] Equity Component [Domain] Subsequent Event Type [Domain] Subsequent Event Type [Domain] 2025 [Member] Loss Carry Forwards Expirations Year Three [Member] Loss Carry Forwards Expirations Year Three Member Ownership [Axis] Ownership [Axis] Kaplan Stock Option and Restricted Stock [Member] Kaplan Stock Option and Restricted Stock [Member] Kaplan Stock Option and Restricted Stock [Member] Increase in net assets from operations Net Assets from Operations, Increase (Decrease) Amount of increase (decrease) in net assets from operations Increases related to current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Loan Receivable Fixed Interest Rate Related Party Transaction, Rate Investment, Name [Domain] Investment, Name [Domain] Loss contingency, estimate of possible loss Loss Contingency, Estimate of Possible Loss Amortization of finance ROU assets Finance Lease, Right-of-Use Asset, Amortization Curtailments and settlements Included in Net Income [Member] Curtailment (Gains) Losses Included in Net Income [Member] AccumulatedDefinedBenefitPlansAdjustmentCurtailmentGainsIncludedInNetIncome [Member] Accumulated other comprehensive (income) loss related to the curtailment gains included in net income component of defined benefit plans attributable to the parent. Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Cumulative foreign currency translation adjustment Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Impairment of a cost method investment Impairment cost method investments Equity Securities without Readily Determinable Fair Value, Impairment Loss, Annual Amount Realized and Unrealized Gain (Loss) on Equity Method Investments and Equity Securities Without Readily Determinable Fair Value Realized and Unrealized Gain (Loss) on Equity Method Investments and Equity Securities Without Readily Determinable Fair Value Amount of realized and unrealized gain (loss) on sale or write-downs of equity method investments or investment in equity security without readily determinable fair value. Unrealized gain on pensions and other postretirement plans Net amount Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets Amount of other assets acquired at the acquisition date. Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Fair value of assets at beginning of year Fair value of assets at end of year Fair Value Defined Benefit Plan, Plan Assets, Amount Deferred Revenue, Period Increase Percentage Deferred Revenue, Period Increase (Decrease) Percentage Deferred Revenue, Period Increase (Decrease) Percentage Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items] Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items] [Line Items] for Disclosures pertaining to an entity's basic and diluted earnings per share. Supplemental Cash Flow Information Supplemental Cash Flow Information [Abstract] Vehicle Floor Plan Facility [Member] Vehicle Floor Plan Facility [Member] Vehicle Floor Plan Facility [Member] Group Dekko [Member] Group Dekko [Member] Group Dekko [Member] Higher Education [Member] Higher Education [Member] Higher Education [Member] Plan Name [Domain] Plan Name [Domain] Balance of costs to obtain a contract Capitalized Contract Cost, Net Deferred Income Tax Liabilities [Table] Deferred Income Tax Liabilities [Table] Deferred Income Tax Liabilities [Table] Noncurrent liabilities Liabilities, Noncurrent Other Indebtedness [Member] Other Indebtedness [Member] Other Indebtedness [Member] Line of credit facility outstanding Credit Facility Long-Term Line of Credit Entity Address, State or Province Entity Address, State or Province Deferred income tax liabilities related to undistributed earnings of investments in non-U.S. subsidiaries Non-U.S. withholding tax Deferred Tax Liabilities, Undistributed Foreign Earnings Sale of equity in subsidiary Noncontrolling Interest, Increase from Sale of Parent Equity Interest Options Outstanding, Weighted Average Remaining Contractual Life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term CARES Act Fund [Axis] CARES Act Fund [Axis] CARES Act Fund Award Type [Axis] Award Type [Axis] Actuarial (gain) loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Interest Rate on Advance to Minority Shareholder Interest Rate on Advance to Minority Shareholder Interest Rate on Advance to Minority Shareholder 2027 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Decreases related to settlement with tax authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Clyde's Restaurant Group [Member] Clyde's Restaurant Group [Member] Clyde's Restaurant Group Total pension and other postretirement plans Total Recognized in Other Comprehensive Income (Before Tax Effects) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Residential And Michigan Hospital Joint Venture [Member] Residential And Michigan Hospital Joint Venture [Member] Residential and a Michigan hospital joint venture [Member] Current portion of lease liabilities Current lease liabilities Operating Lease, Liability, Current Medicare Advantage [Member] Medicare Advantage [Member] Medicare Advantage [Member] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] Number Of Businesses Disposed Number Of Businesses Disposed The number of businesses disposed of by the entity during the period. Transaction [Domain] Transaction [Domain] Pricing Methodology [Domain] Pricing Methodology [Domain] Pricing Methodology [Domain] Supplemental Executive Retirement Plan (SERP) [Member] Supplemental Employee Retirement Plan [Member] Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Property, plant and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Other current investments Other Short-Term Investments Long-Term Debt Total Long-Term Debt Long-Term Debt, Excluding Current Maturities Foreign currency translation adjustments: Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent [Abstract] Income Taxes [Line Items] Income Taxes [Line Items] Income Taxes [Line Items] Total Liabilities Liabilities Leases Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Deferred Rent Cash overdrafts Bank Overdrafts Operating lease, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Measurement period adjustment Goodwill, Purchase Accounting Adjustments Cash Flows from Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Schedule of Estimated Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Number of education business categories Number Of Education Business Categories Number of categories that comprise Kaplan's businesses Tax Expense and Revaluation Valuation Allowances And Reserves, Charged To Cost And Expense And Other Charges Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to costs and expenses and other charges. Increase (Decrease) in Temporary Equity [Roll Forward] Increase (Decrease) in Temporary Equity [Roll Forward] Prior service cost Current year prior service cost Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Fair Value Hierarchy and NAV [Domain] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Conversion of Class A shares to Class B Conversion of Stock, Shares Converted Early Retirement Program Expense [Domain] Early Retirement Program Expense [Domain] -- None. No documentation exists for this element. -- Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Document Type Document Type Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Property, Plant and Equipment, Useful Life (in years) Property, Plant and Equipment, Useful Life Expired or forfeited, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Severance Severance Costs Beginning of year, Average Grant-Date Fair Value (in dollars per share) End of year, Average Grant-Date Fair Value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Cash paid during the year for: Cash Paid During The Year For: [Abstract] -- None. No documentation exists for this element. -- Number of investment companies actively managing plan assets Number Of Investment Companies Managing Plan Assets The number of investment companies actively managing plan assets. Government Relief, CARES Act Government Relief, CARES Act Amount received from the government as relief under the CARES Act Percent allocated to common stockholders Percentage Of Undistributed Earnings Allocated To Common Stockholders Represents the percentage allocation of undistributed earnings to common stockholders. Investments [Abstract] Investments [Abstract] (Benefit from) provision for deferred income taxes Total income tax, Deferred Deferred Income Tax Expense (Benefit) Deferred revenue Increase (Decrease) in Deferred Revenue Prepaid Pension Cost Noncurrent asset Assets for Plan Benefits, Defined Benefit Plan Exercise Price Range [Axis] Exercise Price Range [Axis] Secured Overnight Financing Rates (SOFR) [Member] Secured Overnight Financing Rates (SOFR) [Member] Average rate at which institutions can borrow US dollars overnight while posting US Treasury bonds as collateral. Transition and Operations Support Agreement Initial Term Transition and Operations Support Agreement Initial Term Transition and Operations Support Agreement Initial Term 2003 Employee Stock Option Plan [Member] 2003 Employee Stock Option Plan [Member] 2003 Employee Stock Option Plan reserves shares of the Company's Class B common stock for options to be granted under the plan. [Member] (Repayments of) proceeds from bank overdrafts Proceeds from (Repayments of) Bank Overdrafts Contract with Customer, Liability Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Carryforwards Period [Axis] Operating Loss Carryforwards [Axis] CarryforwardsPeriod [Axis] -- None. No documentation exists for this element. -- Adjustment for sale of a business with foreign operations Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax Total Restructuring Related Costs Restructuring, Settlement and Impairment Provisions Debt Disclosure [Abstract] Debt Disclosure [Abstract] Allowance for Credit Losses Accounts Receivable [Policy Text Block] Loans to related party Payments for Advance to Affiliate Income Statement Location [Axis] Income Statement Location [Axis] Accounts receivable, noncurrent Accounts Receivable, after Allowance for Credit Loss, Noncurrent Company contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Net pension benefit and special separation benefit expense Net Periodic Benefit For Defined Benefit Pension Plans Excluding Curtailment The net periodic benefit or expense for defined benefit pension plans excluding curtailment. Current portion of long-term debt Long-Term Debt, Current Maturities Net Cash (Used in) Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Accounting Policies [Abstract] Accounting Policies [Abstract] Commercial note with Truist Bank maturing in 2032 - $27.2 million [Member] Commercial note with Truist Bank maturing in 2032 - $27.2 million [Member] Commercial note with Truist Bank maturing in 2032 - $27.2 million Variable lease cost Variable Lease, Cost Net gain on sale of businesses Gain (Loss) on Disposition of Business Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Audit Information [Abstract] Audit Information [Abstract] Kaplan Share of Purdue University Global Revenue Kaplan Share of Purdue University Global Revenue Percentage representing Kaplan's fee based on Purdue University Global Revenue Selling, general and administrative Selling, General and Administrative Expenses The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc. Also includes expenses such as bad debt expense, and gain (loss) on disposition of assets. Interest cost Defined Benefit Plan, Interest Cost Private investment fund [Member] Private Equity Funds [Member] Finance Lease, Liability, Noncurrent Finance Lease, Liability, Noncurrent Fair Value of Options Assumptions Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Capital Stock, Stock Awards, and Stock Options [Abstract] Capital Stock, Stock Awards, and Stock Options [Abstract] -- None. No documentation exists for this element. -- Purchase of redeemable noncontrolling interest Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Lease liabilities Increase (Decrease) in Operating Lease Liability Impairment of intangible and other long-lived assets Impairment Of Intangible And Other Long-Lived Assets The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of intangible and other long-lived assets. Schedule of Provision for Income Taxes on Income Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Buildings Buildings and Improvements, Gross Securities Subject to Mandatory Redemption [Member] Securities Subject to Mandatory Redemption [Member] Years over which cost expected to be recognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Options Exercisable, Weighted Average Remaining Contractual Life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term 2026 [Member] Loss Carry Forwards Expirations Year Four [Member] Loss Carry Forwards Expirations Year Four Member Inventories and contracts in progress Inventories and contracts in progress Inventory, Net of Allowances, Customer Advances and Progress Billings Net investment loss Investment gain (loss) Amount of Investment gain (loss) Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Other comprehensive (loss) income before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Gross profit Gross Profit Entity Registrant Name Entity Registrant Name Kaplan University Transaction Termination Fee Kaplan University Transaction Termination Fee Percent of Purdue Global University revenue for preceding 12 month period to be paid to terminate the Transition and Operations Support Agreement 2026 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Percentage of Distributions Available to Common Unit Holders Percentage of Distributions Available to Common Unit Holders Percentage of distributions available to common unit holders Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate High Exercise Price Range Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit Year that reaches ultimate cash balance interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Year Weighted-Average Interest Crediting Rate Reaches Ultimate Rate Year ultimate weighted-average interest crediting rate is expected to be reached, in CCYY format. Series of Individually Immaterial Business Acquisitions [Member] Series of Individually Immaterial Business Acquisitions [Member] Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Options outstanding exercisable in 2026 (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Four Options outstanding exercisable in year four. Pensions and Other Postretirement Plans Retirement Benefits [Text Block] Purchase of noncontrolling interest Payments for Repurchase of Redeemable Noncontrolling Interest Tax loss carryforwards as a result of operating losses and prior stock acquisitions Operating Losses And Prior Stock Acqusitions Carryforward Tax loss carryforwards as a result of operating losses and prior stock acquisitions Leases [Abstract] Leases [Abstract] Subsegments [Axis] Subsegments [Axis] Total Equity As of As of Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Exercise Price Above Fair Market Value Of Common Stock [Member] Exercise Price Above Fair Market Value Of Common Stock [Member] -- None. No documentation exists for this element. -- Minimum [Member] Minimum [Member] Entity Emerging Growth Company Entity Emerging Growth Company Pinnacle Bank Loan & Security Agreement [Member] Pinnacle Bank Loan & Security Agreement [Member] Pinnacle Bank Loan & Security Agreement [Member] Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Framebridge [Member] Framebridge [Member] Framebridge [Member] Accrual balance related to stock based compensation Deferred Compensation Share-Based Arrangements, Liability, Current and Noncurrent Other Comprehensive Income (Loss) before Reclassifications, Tax Other Comprehensive Income (Loss) before Reclassifications, Tax SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Investments in equity affiliates, cost method and other investments Payments To Acquire Equity Method Cost Method Investments And Other Investments The cash outflow associated with the purchase of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence, cost method investments or other investments, not including marketable equity securities. Investment, Name [Axis] Investment, Name [Axis] Fair Value Measurements Fair Value Disclosures [Text Block] Distribution to noncontrolling interests Temporary Equity, Distribution to noncontrolling interests Decrease in redeemable noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. Valuation allowance related to operating loss carryforwards Operating Loss Carryforwards, Valuation Allowance Trading Symbol Trading Symbol Entity File Number Entity File Number GBP revolving credit facility borrowings [Member] GBP revolving credit facility borrowings [Member] GBP revolving credit facility borrowings Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Carryforward Period [Domain] Operating Loss Carryforward Period [Domain] Carryforward Period [Domain] Carryforward Period Domain Estimated amortization of intangible assets, 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Four KIHL [Member] KIHL [Member] KIHL [Member] Transaction Type [Axis] Transaction Type [Axis] Deferred revenue Deferred Revenue, Current Comprehensive (income) loss attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Accelerated depreciation of property, plant and equipment Restructuring and Related Cost, Accelerated Depreciation Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Non-U.S., Deferred Deferred Foreign Income Tax Expense (Benefit) Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits, by Title of Individual [Axis] Title of Individual [Axis] Summary of Significant Accounting Policies [Line Items] Summary of Significant Accounting Policies [Line Items] -- None. No documentation exists for this element. -- Other Deferred Tax Assets, Tax Deferred Expense, Other Number of shares awarded Awarded, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Schedule of Income Tax Loss Carryforwards Summary of Operating Loss Carryforwards [Table Text Block] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Income (Loss) from Operations before Amortization of Intangible Assets and Impairment of Goodwill and Other Long-Lived Assets Operating Income before Amortization of Intangible Assets and Impairment of Goodwill and Other Long-Lived Assets. Operating Income before Amortization of Intangible Assets and Impairment of Goodwill and Other Long-Lived Assets. Estimated employer contributions in next fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year 2024 [Member] Loss Carry Forwards Expirations Year Two [Member] Loss Carry Forwards Expirations Year Two [Member] Use of Estimates Use of Estimates, Policy [Policy Text Block] Other Nonoperating Income (Expense) [Abstract] Other Nonoperating Income (Expense) [Abstract] 2020 Options Granted [Member] 2017 Options Granted [Member] 2017 Options Granted [Member] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Prime Rate [Member] Prime Rate [Member] Minimum percentage of total assets considered as significant concentrations Minimum percentage of plan assets considered as significant concentrations in pension plans Concentration Risk, Percentage Celtic Healthcare Allegheny Health Network Joint Venture [Member] CelticHealthcareAlleghenyHealthNetworkJointVenture [Member] A joint venture formed between Celtic Healthcare and Allegheny Health Network Volatility, maximum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Pro Forma Net income Business Acquisition, Pro Forma Net Income (Loss) Acquisitions And Dispositions [Abstract] Acquisitions And Dispositions [Abstract] Acquisitions and Dispositions Settlement Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Income Taxes Income Tax Disclosure [Text Block] Revenue from Related Parties Revenue from Related Parties Finished goods Inventory, Finished Goods, Net of Reserves Cash Equivalents [Member] Defined Benefit Plan, Cash and Cash Equivalents [Member] Basic net income per common share (in USD per share) Earnings Per Share, Basic Periodic Cost [Member] Periodic Cost [Member] Periodic cost assumptions. Settlement included in net income Curtailments and settlements Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax Construction in progress Construction in Progress, Gross Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Aggregate Purdue University Global Cash Operating Losses Aggregate Purdue University Global Cash Operating Losses Aggregate Purdue University Global cash operating losses threshold for option to terminate Transition and Operations Support Agreement Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Reclassifications, before tax Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Corporate office [Member] Corporate, Non-Segment [Member] Cash flow hedges gain (loss) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax Transaction Type [Domain] Transaction Type [Domain] Transaction Type [Domain] Programs to Cease New Enrollments, Number Programs to Cease New Enrollments, Number Programs to Cease New Enrollments, Number Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Prepaid expenses Prepaid Expense, Current Home Health Revenue [Member] Home Health Revenue [Member] Home Health Revenue [Member] Actuarial (loss) gain Current year actuarial gain (loss) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Ownership [Domain] Ownership [Domain] Entity Interactive Data Current Entity Interactive Data Current Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Kaplan Singapore [Member] Kaplan Singapore [Member] Kaplan Singapore Change in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Lessee, operating lease, lease not yet commenced, payments due Lessee, Operating Lease, Lease Not yet Commenced, Payments Due Payments due for operating lease arrangements which have not yet commenced as of the date of the balance sheet Floor plan assistance Vehicle Floor Plan Facility Assistance The amount of assistance received from the manufacturers recognized as a reduction of operating expenses. Options outstanding exercisable in 2025 (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Three Options outstanding exercisable in year three. Cumulative realized gain on marketable securities Marketable Securities, Realized Gain (Loss) Period of Transition Operations and Support Agreement [Domain] Period of Transition Operations and Support Agreement [Domain] [Domain] for Period of Transition Operations and Support Agreement [Axis] Common shares repurchased Cost of shares repurchased by company Payments for Repurchase of Common Stock Class of Stock [Axis] Class of Stock [Axis] Income Taxes Income Tax, Policy [Policy Text Block] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Purdue University Global [Member] Purdue University Global [Member] Purdue University Global Summary of Amounts and Line Items of Reclassifications out of Accumulated Other Comprehensive Income (Loss) Disclosure of Reclassification Amount [Text Block] Hospice Revenue [Member] Hospice Revenue [Member] Hospice Revenue [Member] Current Assets Assets, Current [Abstract] Number of Equity Method Investments Impaired Number of investments in affiliates impaired Number of Equity Method Investments Impaired The number of equity method investments impaired during the period. Less: Net losses (gains) in earnings from marketable equity securities sold and donated Equity Securities, FV-NI, Realized Gain (Loss) Advance to Minority Shareholder Advance to Minority Shareholder Advance to Minority Shareholder Contract with Customer, Asset, Net, Noncurrent Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Gross unrealized gains Equity Securities FV-NI, Accumulated Gross Unrealized Gain Amount of unrealized gain on investment on equity security measured at fair value with change in fair value recognized in net income (FV-NI). Retained earnings Retained Earnings (Accumulated Deficit) AOCI Including Portion Attributable to Noncontrolling Interest [Member] AOCI Including Portion Attributable to Noncontrolling Interest [Member] Settlement Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Megaphone [Member] Megaphone [Member] Megaphone Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Kaplan University Transaction [Member] Kaplan University Transaction [Member] Kaplan University Transaction [Member] Scenario [Domain] Scenario [Domain] Programs Still Offered, Number Programs Still Offered, Number Programs Still Offered, Number Accounts receivable Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Accounts Receivable, Allowance for Credit Loss Fair Value, Recurring [Member] Fair Value, Recurring [Member] Options Exercisable, Weighted Average Exercise Price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Acquisition Pro Forma Financial Information Business Acquisition, Pro Forma Information [Table Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Kaplan [Member] Kaplan [Member] Kaplan [Member] Inventory, Net of Allowances, Customer Advances and Progress Billings [Abstract] Inventory, Net of Allowances, Customer Advances and Progress Billings [Abstract] Cost of services and goods Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Pricing Methodology [Axis] Pricing Methodology [Axis] Pricing Methodology Income before Income Taxes [Abstract] Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest [Abstract] Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Financing cash flows from finance leases (payments) Finance Lease, Principal Payments Indefinite-lived Intangible Assets [Line Items] Indefinite-Lived Intangible Assets [Line Items] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Loss Contingencies [Table] Loss Contingencies [Table] Total income tax, Current Current Income Tax Expense (Benefit) Goods [Member] Product [Member] Future minimum sublease payments due Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Retirement Benefits Disclosure [Line Items] Retirement Benefits Disclosure [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Evaluation of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Product Information [Line Items] Product Information [Line Items] Prior Period Reclassification Adjustment Prior Period Reclassification Adjustment Equity Method Investment, Nonconsolidated Investee [Axis] Equity Method Investment, Nonconsolidated Investee [Axis] Inventories Increase (Decrease) in Inventories Credit facility current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Cost method investments Equity Securities without Readily Determinable Fair Value, Amount Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Goodwill, Net Goodwill Goodwill, net, beginning balance Goodwill, net, ending balance Goodwill Treasury Stock, Shares Treasury Stock, Shares Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Equity funds [Member] Equity Funds [Member] Issuance of noncontrolling interest Noncontrolling Interest, Increase from Subsidiary Equity Issuance Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Provision for Income Taxes Total provision for income tax Income Tax Expense (Benefit) Geographical [Domain] Geographical [Domain] Valuation Allowance, Amount Valuation allowance Deferred Tax Assets, Valuation Allowance Deferred Income Taxes Deferred Income Tax Liabilities, Net Revenue Source [Axis] Revenue Source [Axis] Revenue Source [Axis} Entity Public Float Entity Public Float Receivables for settlement of investments purchased, net [Member] Receivables (Payables) [Member] -- None. No documentation exists for this element. -- Balance Sheet Location [Domain] Balance Sheet Location [Domain] Residential Home Health Illinois and Residential Hospice Illinois [Member] Residential Home Health Illinois and Residential Hospice Illinois [Member] Residential Home Health Illinois and Residential Hospice Illinois Net (Income) Loss Attributable to Noncontrolling Interests Income (Loss) Attributable to Redeemable Noncontrolling Interest and Nonredeemable Noncontrolling Interest Amount of Net Income (Loss) attributable to redeemable noncontrolling interest and nonredeemable noncontrolling interest. Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Loss Contingencies [Line Items] Loss Contingencies [Line Items] 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year One July 1, 2022 through June 30, 2027 [Member] July 1, 2022 through June 30, 2027 [Member] Period of time July 1, 2022 through June 30, 2027 for which the TOSA term applies (Years 5-9) Forney [Member] Forney [Member] Forney [Member] Accounts payable and accrued liabilities Total accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Value of investments Investments Common stock Common Stock, Value, Issued Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Minimum Term of Contract Minimum Term of Contract Minimum Term of Contract Pre-Age 65 [Member] Pre-Age 65 [Member] Pre-Age 65 [Member] Antidilutive Weighted Average Restricted Stock and Options Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Current liability Liability, Defined Benefit Plan, Current Cash and Cash Equivalents and Restricted Cash at Beginning of Year Cash and Cash Equivalents and Restricted Cash at End of Year Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Non-U.S. Income (Loss) from Continuing Operations before Income Taxes, Foreign Recipient of Consideration [Axis] Recipient of Consideration [Axis] Recipient of Consideration Kaplan Corporate and Other [Member] Kaplan Corporate and Other [Member] Kaplan Corporate And Other [Member] Current Liabilities Liabilities, Current [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Proceeds from exercise of stock options Proceeds from Stock Options Exercised Curtailment Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Acquisition of business Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Interest on lease liabilities Finance Lease, Interest Expense Schedule of Changes in Deferred Tax Valuation Allowance Summary of Valuation Allowance [Table Text Block] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification out of Accumulated Other Comprehensive Income [Member] Income Statement Location [Domain] Income Statement Location [Domain] Contingent consideration liabilities [Member] Contingent consideration liabilities [Member] Contingent consideration liabilities Amendment Flag Amendment Flag Derivative, Basis Spread on Variable Rate Derivative, Basis Spread on Variable Rate Amortized Intangible Assets, Useful Life (in years) Useful Life (in years) Finite-Lived Intangible Asset, Useful Life Operating lease cost Operating Lease, Cost USD revolving credit facility borrowings [Member] USD revolving credit facility borrowings [Member] USD revolving credit facility borrowings Undistributed earnings Undistributed Earnings, Basic Investment Type [Axis] Investment Type [Axis] Other Comprehensive (Loss) Income, Net of Tax Other comprehensive income (loss), net of income taxes Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Net of Tax Impairment Of Intangible Asset Indefinite Lived Excluding Goodwill Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag Impairment Of Intangible Asset Indefinite Lived Excluding Goodwill Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag Impairment Of Intangible Asset Indefinite Lived Excluding Goodwill Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag Acquisitions Goodwill, Acquired During Period Operating Lease Cost Operating Lease Abandonment Cost Amount of lease cost, calculated by allocation of remaining cost of lease over remaining lease term, due to early abandonment of lease in part of restructuring plan. Pro Forma Operating revenues Business Acquisition, Pro Forma Revenue Acquisitions and Dispositions of Businesses Mergers, Acquisitions and Dispositions Disclosures [Text Block] Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Annual Purdue University Global Cash Operating Losses Annual Purdue University Global Cash Operating Losses Annual Purdue University Global cash operating losses threshold for option to terminate Transition and Operations Support Agreement Schedule of Amounts Recognized in Accumulated Other Comprehensive Income (Loss) Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Deferred Charges and Other Assets (includes $646 and $782 of restricted cash) Other Assets, Noncurrent Goodwill and Other Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Options Exercisable, Shares Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Education [Member] Education [Member] Education [Member] Early Retirment Program Expense [Domain] Early Retirment Program Expense [Domain] Early Retirment Program Expense [Domain] Estimated amortization of intangible assets, after 2027 Finite-Lived Intangible Asset, Expected Amortization, after Year Five Graham Holdings Company Common Stockholders: Income Per Share From Continuing Operations To Common Stockholders [Abstract] Income Per Share From Continuing Operations To Common Shareholders. Operating Costs and Expenses Operating Costs and Expenses [Abstract] Change in redemption value of redeemable noncontrolling interests Temporary Equity, Change in Redemption Value Change in temporary equity during the period as a result of a change in the redemption value of redeemable noncontrolling interest. Investment Manager 1 [Member] Investment Manager 1 [Member] Investment Manager 1 [Member] Counterparty Name [Axis] Counterparty Name [Axis] Reportable Subsegments [Member] Reportable Subsegments [Member] Television Broadcasting [Member] Television Broadcasting [Member] Television Broadcasting [Member] Claims discharge loan amount Loss Contingency Borrower Defense Claims Discharge Loan Amount The amount of money applications seek to discharge of loans. Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Other Healthcare Services [Member] Other Healthcare Services [Member] Other Healthcare Services [Member] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Non-U.S.deferred tax asset related to capital loss carryforwards Capital loss carryforwards Deferred Tax Assets, Capital Loss Carryforwards Amortized intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Berkshire Hathaway Common Stock [Member] Berkshire Hathaway Common Stock [Member] Berkshire Hathaway Common Stock [Member] Noncontrolling interest capital contributions Temoporary Equity, Increase from capital contributions Amount of increase in redeemable noncontrolling interest from capital contributions from redeemable noncontrolling interests Operating cash flows from operating leases (payments) Operating Lease, Payments Share-based Payment Arrangement, Option [Member] Stock Option Plan [Member] Share-Based Payment Arrangement, Option [Member] Cost of 15,213,398 and 15,093,934 shares of Class B common stock held in treasury Treasury Stock, Value Volatility (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Other Non-Operating Income Other Income and Other Expense Disclosure [Text Block] Provider Relief Fund [Member] Provider Relief Fund [Member] Provider Relief Fund under the CARES Act Common Stock, Shares Authorized Common Stock, Shares Authorized Income taxes payable Accrued Income Taxes, Current Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Operating Expenses Operating Expenses Maximum [Member] Maximum [Member] Basis of Presentation and Principles of Consolidation Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Depreciation, amortization and goodwill and other long-lived asset impairment Depreciation, Depletion, Amortization And Impairment The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets, including write-downs for impairments. Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accretion of value included in net income Fair​ Value, ​Measurement​ With ​Unobservable ​Inputs ​Reconciliations, ​Recurring ​Basis, ​Liability​, Gain (Loss), Accretion Included in Earnings Amount of gain (loss) recognized in income from accretion from liability measured at fair value on recurring basis using unobservable input (level 3). (Loss) gain on marketable equity securities, net (Loss) gain on marketable equity securities, net Equity Securities, FV-NI, Gain (Loss) Business Acquisition [Line Items] Business Acquisition [Line Items] Interest rate swap Interest Rate Cash Flow Hedge Liability at Fair Value Foreign currency exchange rate changes Fair​ Value, ​Measurement​ With ​Unobservable ​Inputs ​Reconciliations, ​Recurring ​Basis, ​Liability​, Foreign Currency Translation Gain (Loss), Amount of foreign currency translation of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Measurement Frequency [Domain] Measurement Frequency [Domain] Sublease rental income Operating Leases, Income Statement, Sublease Revenue Schedule of Net (Benefit) Costs Schedule of Net Benefit Costs [Table Text Block] Income tax loss carryforwards obtained as a result of prior stock acqusitions Income tax loss carryforwards to be fully utilized Tax Loss Carryforward Prior Stock Acquisition Utilized Income tax loss carryforwards obtained as a result of prior stock acqusitions to be fully utilized. Accounts Receivable Accounts Payable And Accrued Liabilities Accounts Receivable Accounts Payable And Accrued Liabilities [Text Block] The entire disclosure of Accounts Receivable Accounts Payable And Accrued Liabilities Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Indefinite-lived intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets GHC One [Member] GHC One and GHC Two [Member] GHC One [Member] Gain Related to Contingent Consideration Gain related to contingent consideration Gain Related to Contingent Consideration Contingent consideration gain related to the sale of a business. Percentage of total plan assets Defined Benefit Plan Assets Allocation (Percent) Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Other indebtedness Other Long-Term Debt Sublease income Sublease Income Number of Stores Number of dealerships Number of Stores Accounts receivable Increase (Decrease) in Accounts Receivable Title of 12(b) Security Title of 12(b) Security Share awards outstanding, restriction will lapse in 2025 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year Three Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year Three Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Fixed income securities [Member] Fixed Income Securities [Member] Maximum Term of Contract Maximum Term of Contract Maximum Term of Contract Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Schedule of Unrecognized Tax Benefits Roll Forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Schedule of Assumptions Used Defined Benefit Plan, Assumptions [Table Text Block] Business Segments Segment Reporting Disclosure [Text Block] Equity Method Investment, Nonconsolidated Investee [Domain] Equity Method Investment, Nonconsolidated Investee [Domain] Other receivables Other Receivables Stock based compensation Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-Based Payment Arrangement, Amount CSI Pharmacy Holding Company, LLC [Member] CSI Pharmacy Holding Company, LLC [Member] CSI Pharmacy Holding Company, LLC [Member] Total finance lease cost Total finance lease cost Total finance lease cost Deferred Income Tax Liabilities, Net Deferred Tax Liabilities, Net Purchase of redeemable noncontrolling interest Equity effect of redemption of redeemable noncontrolling interest Equity effect of redemption of redeemable noncontrolling interest Liabilities and Equity Liabilities and Equity [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Expired or forfeited, Average Option Price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Other Intangible Assets Schedule of Finite and Indefinite Lived Intangible Assets [Table Text Block] Schedule of Finite and Indefinite Lived Intangible Assets [Table Text Block] Accounts payable Accounts Payable, Current Number of businesses acquired Number of Businesses Acquired Income Tax Authority [Axis] Income Tax Authority [Axis] Number of Restaurants Number of Restaurants Total cost Equity Securities, FV-NI, Cost Number of marketable equity securities greater than 5% of total assets Number of marketable equity securities greater than 5% of total assets Number of marketable equity securities greater than 5% of total assets Amount of Priority Payment Per Year Beyond Costs Amount of Priority Payment Per Year Beyond Costs Amount of priority payment made to Purdue University Global beyond costs before any payment to Kaplan Lease right-of-use assets Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Lease Right-of-Use Asset Amount of lease right of use assets assumed in business combination Schedule of Product Information [Table] Schedule of Product Information [Table] Basic average number of common shares outstanding (in shares) Weighted average shares outstanding (shares) Weighted Average Number of Shares Outstanding, Basic Percentage of Additional Ownership Available to be Acquired Percentage of Additional Ownership Available to be Acquired The percentage of additional ownership available to be acquired by the minority shareholder. Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Ultimate cash balance interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Ultimate Weighted-Average Interest Crediting Rate Ultimate weighted-average interest crediting rate used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate. Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Stock compensation payouts Deferred Compensation Arrangement with Individual, Distribution Paid Defined benefit plan, target allocation percentage of assets Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Gain on disposition and write-downs of businesses, property, plant and equipment, investments and other assets, net Gain (Loss) on Disposition of Assets Accounts receivable Accounts Receivable, after Allowance for Credit Loss Derivative, Notional Amount Derivative, Notional Amount 2027 [Member] Loss Carry Forwards Expirations Year Five [Member] Loss Carry Forwards Expirations Year Five Member Preferred Stock, $1 par value; 977,000 shares authorized, none issued Preferred Stock, Value, Issued Assumed health care cost trend rate Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year Redeemable Noncontrolling Interests As of As of Redeemable Noncontrolling Interest, Equity, Carrying Amount Restricted Stock [Member] Restricted Stock [Member] Financial Instruments Subject to Mandatory Redemption, Financial Instrument [Domain] Financial Instruments Subject to Mandatory Redemption, Financial Instrument [Domain] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Five-Year Credit Agreement maturing in 2027 [Member] Five-Year Credit Agreement maturing in 2027 [Member] Five-Year Credit Agreement maturing in 2027 Less: current portion Debt, Current Business Combinations Business Combinations and Other Purchase of Business Transactions, Policy [Policy Text Block] Leases Lessee, Leases [Policy Text Block] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Noncurrent assets Assets, Noncurrent Estimated credit losses Accounts Receivable, Allowance for Credit Loss Total investments [Member] Total Investments [Member] -- None. No documentation exists for this element. -- Work-in-process Inventory, Work in Process, Net of Reserves Marketplace Strategy [Member] Marketplace Strategy [Member] Marketplace Strategy [Member] Potential claims per ED LossContingencyPotentialBorrowerDefenseClaimsPerEDNumber The number of potential borrower defense claims per the Department of Education (ED). Noncontrolling Interest [Member] Noncontrolling Interest [Member] Dispositions Goodwill, Written off Related to Sale of Business Unit Cumulative undistributed income in investments in affiliates Retained Earnings, Undistributed Earnings from Equity Method Investees Interest Expense, Net Interest Income (Expense), Net Debt Instrument, Term Debt Instrument, Term Operating Expense Operating Expense [Member] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Investments in marketable equity securities and other investments Investments In Marketable Equity Securities And Other Investments Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale which are intended to be held for less than one year or the normal operating cycle, whichever is longer. Also includes other current investments such as mutual funds. Goodwill [Roll Forward] Goodwill [Roll Forward] Net Loss Attributable to Redeemable Noncontrolling Interest Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Add: Effect of dilutive stock options (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] Graham Healthcare Group [Member] Graham Healthcare Group [Member] Graham Healthcare Group [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Leaf Group [Member] Leaf Group [Member] Leaf Group Investments in certain businesses, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired U.S. stock index fund [Member] Equity Funds, US [Member] An investment that pools funds from many investors to invest in a combination of underlying investments, primarily equity investments, domiciled in United States of America (US). Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Goodwill expected to be deductible for income tax purposes Business Acquisition, Goodwill, Expected Tax Deductible Amount Current Fiscal Year End Date Current Fiscal Year End Date Amortized Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Inventory [Line Items] Inventory [Line Items] Amortization of unearned stock compensation and stock option expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Less: Dividends paid–common stock outstanding and unvested restricted shares Dividends Paid Common Stock And Share-based Compensation-Cash Amount of paid and unpaid common stock dividends declared with the form of settlement in cash and amount of paid and unpaid cash dividends declared and applicable to holders of share-based compensation, for example, but not limited to, non-vested shares, stock options, or restricted stock units. Investment Managers [Axis] Investment Managers [Axis] Investment Managers [Axis] Interest Rate Swap maturing in 2032 - $27.2 million [Member] Interest Rate Swap maturing in 2032 - $27.2 million [Member] Forward based contracts in which two parties agree to swap periodic payments that are fixed at the outset of the swap contract with variable payments based on a market interest rate (index rate) over a specified period. Concentration Risk by Type [Axis] Concentration Risk Type [Axis] Total Current Liabilities Current liabilities Liabilities, Current Interest rate, minimum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Education Programs [Axis] Education Programs [Axis] Education Programs Tax loss carryforwards from operating losses and prior stock acquisitions that can be carried forward indefinitely Operating Losses And Prior Stock Acqusitions Carryforward Indefinitely Tax loss carryforwards from operating losses and prior stock acquisitions that can be carried forward indefinitely. Inventory, Current [Table] Inventory, Current [Table] Schedule of Accounts Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Self-Insurance Self Insurance Reserve [Policy Text Block] Floor plan payable Floor plan payables Vehicle floor plan payable Vehicle Floor Plan Facility Payable The amount borrowed to finance the purchase of specific vehicle inventories. Other, net Other Nonoperating Gains (Losses) Income Tax Expense (Benefit), Continuing Operations [Abstract] Income Tax Expense (Benefit), Continuing Operations [Abstract] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Unrecognized tax benefit that would impact the effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Loans Payable to Bank Loans Payable to Bank Pinnacle Bank Term Loan [Member] Pinnacle Bank Term Loan maturing in 2024 [Member] Pinnacle Bank Term Loan [Member] Term loan with Pinnacle Bank FCC licenses [Member] Operating and Broadcast Rights [Member] Automotive [Member] Automotive [Member] Automotive [Member] Interest rate, maximum Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Net unrealized (losses) gains in earnings from marketable equity securities still held at the end of the year Equity Securities, FV-NI, Unrealized Gain (Loss) Accounts receivable, net Accounts receivable, net Accounts and Other Receivables, Net, Current Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit Low Exercise Price Range Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit Number of Performance Obligations Number of Performance Obligations Number of Performance Obligations in standard contract Income Tax Authority [Domain] Income Tax Authority [Domain] Other Proceeds from (Payments for) Other Financing Activities Share-based Payment Arrangement, Option, Exercise Price Range [Table] Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Loss (gain) on marketable equity securities and cost method investments, net Unrealized Gain (Loss) on Investments Impairment of intangible assets Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill) Finance lease, fixed cost Finance Lease, Fixed Cost Finance Lease, Fixed Cost Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Finance Lease, Weighted Average Remaining Lease Term Finance Lease, Weighted Average Remaining Lease Term Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Accounts Payable and Accrued Liabilities, Current [Abstract] Accounts Payable and Accrued Liabilities, Current [Abstract] 2022 Incentive Compensation Plan 2022 Incentive Compensation Plan [Member] 2022 Incentive Compensation Plan Debt [Table] Debt [Table] Schedule of all debt, including both short term and long term. Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Vested, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period 2026 [Member] 2026 [Member] 2026 [Member] Entity Tax Identification Number Entity Tax Identification Number Shares reserved for stock awards granted under the plan Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Schedule of Investments [Table] Schedule of Investments [Table] Federal tax impact of unrecognized tax benefits that would impact the effective tax rate Federal Tax Impact Of Unrecognized Tax Benefits that Would Impact Effective Tax Rate The federal tax impact of the total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. Derivative, Fixed Interest Rate Derivative, Fixed Interest Rate Skin Clique Skin Clique [Member] Skin Clique Employee benefit obligations Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Net loss attributable to redeemable noncontrolling interests Temporary Equity, Net Income Exercise Price $719 [Member] Price Range Three [Member] Exercise Price of $719 Unrecognized actuarial (gain) loss Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Net Increase (Decrease) in Cash and Cash Equivalents and Restricted Cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Residential Home Health Illinois [Member] Residential Home Health Illinois [Member] Residential Home Health Illinois [Member] State and local taxes, net of U.S. Federal tax Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Schedule of Restructuring Costs Restructuring and Related Costs [Table Text Block] Entity Central Index Key Entity Central Index Key Amortization of Intangible Assets Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Interest income Investment Income, Interest Other Comprehensive (Loss) Income, Before Tax Other Comprehensive Income (Loss), before Tax [Abstract] Options outstanding exercisable in 2027 (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Six Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Six Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Management Fee Management Fee Management fee payable by the Company in connection with management services provided under the management services agreement Cost of acquisition Business Combination, Consideration Transferred Summary of Other Comprehensive Income (Loss) Comprehensive Income (Loss) [Table Text Block] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Entity [Domain] Entity [Domain] City Area Code City Area Code Assets Assets [Abstract] Accounts and Financing Receivable, after Allowance for Credit Loss [Abstract] Accounts and Financing Receivable, after Allowance for Credit Loss [Abstract] Other assets and other liabilities, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Unfunded Commitment Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Recognized asset (liability) Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position Defined Benefit Plan Health Care Cost Trend Groups [Domain] Defined Benefit Plan Health Care Cost Trend Groups [Domain] Defined Benefit Plan Health Care Cost Trend Groups [Domain] Total foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Total Financial Liabilities Financial Liabilities Fair Value Disclosure Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Professional Publications, Inc. [Member] Professional Publications, Inc. [Member] Professional Publications, Inc. Stock-based compensation expense, net of forfeitures Share-Based Payment Arrangement, Noncash Expense Additional investment in equity affiliates Payments to Acquire Equity Method Investments Weighted average fair value, granted options (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Variable Rate [Axis] Variable Rate [Axis] Other Liabilities Other Liabilities, Noncurrent Equity in (losses) earnings of affiliates, net Equity in (Losses) Earnings of Affiliates, Net Income (Loss) from Equity Method Investments Net Periodic Cost (Benefit) for the Year Net Periodic Benefit For Defined Benefit Pension Plans Excluding Early Retirement Program, Special Separation Benefit Expense, Curtailment And Settlement The net periodic benefit or expense for defined benefit pension plans excluding the early retirement program and special separation benefit expense, curtailment, settlement and other programs separately disclosed in the financial statements. Purchases of property, plant and equipment Payments to Acquire Property, Plant, and Equipment Machinery, equipment and fixtures Machinery and Equipment, Gross Long-term Purchase Commitment, Amount Long-Term Purchase Commitment, Amount Estimated amortization of intangible assets, 2023 Finite-Lived Intangible Asset, Expected Amortization, Year One Benefit obligation at begining of year Benefit obligation at end of year Defined Benefit Plan, Benefit Obligation Summary of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Right-of-use assets obtained in exchange for operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability College for Financial Planning [Member] College for Financial Planning [Member] College for Financial Planning Other Postretirement Plans [Member] Other Postretirement Benefits Plan [Member] Mandatorily Redeemable Noncontrolling Interest Mandatorily Redeemable Noncontrolling Interest [Policy Text Block] Mandatorily Redeemable Noncontrolling Interest [Policy Text Block] Advertising Revenue [Member] Advertising Revenue [Member] Advertising Revenue [Member] After June 30, 2048 [Member] After June 30, 2048 [Member] Period of time after June 30, 2048 (thirtieth year) for which the TOSA term applies Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Net amount reclassified from accumulated other comprehensive income Reclassifications, net of tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Rate of compensation increase (percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Leases, operating lease, liability, payments, due, total Lessee, Operating Lease, Liability, to be Paid Net Income Net Income Net income for the year Net Income (Loss) Net of Tax Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Amortization of Intangible Assets and Impairment of Goodwill and Other Long-Lived Assets Amortization Of Intangible Assets And Impairment Of Goodwill And Other Long-Lived Assets Amortization of intangible assets and impairment of goodwill and other long-lived assets during the period. Entity Address, Postal Zip Code Entity Address, Postal Zip Code Revenue Remaining Performance Obligation Percentage of Revenue Expected to be Recognized Over Next 12 Months Revenue Remaining Performance Obligation Percentage of Revenue Expected to be Recognized Over Next 12 Months Revenue Remaining Performance Obligation Percentage of Revenue Expected to be Recognized Over Next 12 Months Period of Transition Operations and Support Agreement [Axis] Period of Transition Operations and Support Agreement [Axis] Period of Transition Operations and Support Agreement [Axis] Code3 [Member] Code3 [Member] Code3 Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Change in redemption value of redeemable noncontrolling interests Noncontrolling Interest, Change in Redemption Value Total Financial Assets Investments, Fair Value Disclosure Amendments Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment Other Businesses [Member] Other Businesses [Member] Other Segments [Member] Gain on sale of cost method investments Equity Securities without Readily Determinable Fair Value, FV-NI, Realized Gain (Loss) Amount of realized gain (loss) from sale of investment in equity security without readily determinable fair value with change in fair value recognized in net income (FV-NI). Valuation Allowance [Line Items] Valuation Allowance [Line Items] Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Property, plant and equipment Deferred Tax Liabilities, Property, Plant and Equipment Accrued restructuring costs Restructuring Reserve Deductions SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction U.S. equities [Member] Defined Benefit Plan, Equity Securities, US [Member] Defined benefit plan, target allocation maximum percentage of assets, singular equity security, without prior approval by plan administrator Defined Benefit Plan Target Allocation Percentage Of Assets Singular Equity Security Limit Without Approval Of Plan Administrator Target allocation maximum percentage of investment in a single equity security to total plan assets without prior approval of plan administrator. 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Acquisition of redeemable noncontrolling interest Equity Effect of Acquisition of Redeemable Noncontrolling Interest Equity Effect of Acquisition of Redeemable Noncontrolling Interest Total Cost (Benefit) for the Year Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Kaplan Australia [Member] Kaplan Australia [Member] Kaplan Australia [Member] U.S. Federal [Member] Domestic Tax Authority [Member] Foreign tax credit carryforwards Foreign Tax Credit Carryforwards Foreign tax credits available to be credited against future U.S. Federal income tax liabilities. Vesting Condition [Axis] Vesting Condition [Axis] Vesting Condition Foreign exchange swap Foreign Currency Contracts, Liability, Fair Value Disclosure Repurchase of Class B common stock Treasury Stock, Value, Acquired, Cost Method Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Net Income Attributable to Graham Holdings Company Common Stockholders Net income (loss) attributable to the entity Net income attributable to Graham Holdings Company common stockholders Net Income (Loss) Attributable to Parent Auto dealerships [Member] Auto dealerships [Member] Auto dealerships Other [Member] Other Intangible Assets [Member] Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] Amortization of prior service cost (credit) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Subsequent Event Type [Axis] Subsequent Event Type [Axis] Rate of compensation increase (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Capital contributions Fair Value, Measurement With Unobservable Inputs Reconciliations, Recurring Basis, Liability, Capital Contributions Fair Value, Measurement With Unobservable Inputs Reconciliations, Recurring Basis, Liability, Capital Contributions Scenario [Axis] Scenario [Axis] Guaranteed Return Guaranteed Return Preferred annual return on portfolio investments guaranteed to the Company Valuation allowance against tax benefits Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Leases Lessee, Operating Leases [Text Block] Lessee, operating lease, lease not yet commenced, term of contract Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract Incremental stock compensation expense, net of forfeitures, due to modification Share-Based Payment Arrangement, Plan Modification, Incremental Cost Plan Name [Axis] Plan Name [Axis] Average borrowings outstanding Average Outstanding Debt Amount Average borrowings outstanding during the period, both short and long term. Kaplan Restricted Stock [Member] Kaplan Restricted Stock [Member] -- None. No documentation exists for this element. -- Executive Officer Executive Officer [Member] Goodwill and other intangible assets Deferred Tax Liabilities, Goodwill and Intangible Assets Mandatorily Redeemable Noncontrolling Interest Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount, Noncurrent Deferred state income tax asset State income tax loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, State and Local Goodwill [Line Items] Goodwill [Line Items] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Separation Incentive Program [Member] Separation Incentive Program [Member] Separation Incentive Program [Member] Acquisitions Defined Benefit Plan, Benefit Obligation, Business Combination Number of television broadcast stations owned Number Of Television Broadcast Stations Owned Number of television broadcast stations owned by the Company. Unrecognized prior service cost Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax 2023 [Member] Loss Carry Forwards Expirations Year One [Member] Loss Carry Forwards Expirations Year One Member Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Defined Benefit Plans Disclosures Defined Benefit Plans Assumption [Axis] Defined Benefit Plans Disclosures Defined Benefit Plans Assumption [Axis] Reflects the description and required disclosures pertaining to the entity's defined benefits pension, by plan or groupings of similar plans. Revenues of acquired companies since acquisition date Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Activity Related to Stock Awards Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Settlements or distributions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements York Joint Venture [Member] York Joint Venture [Member] York Joint Venture [Member] Non-operating pension and postretirement benefit income, net Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Number of stock options forfeited due to modification Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Income tax loss carryforwards to expire Income Tax Loss Carryforwards Subject to Expiration Income tax loss carryforwards subject to expiration. Franchise Rights [Member] Franchise Rights [Member] Document Annual Report Document Annual Report Schedule of Non-Operating Income [Line Items] Schedule of Non-Operating Income (Expense) [Line Items] [Line Items] for Schedule of Non-Operating Income (Expense) [Table] Liability Class [Axis] Liability Class [Axis] Sterling Overnight Interbank Average Rate (SONIA) [Member] Sterling Overnight Interbank Average Rate (SONIA) [Member] Average of the interest rates that banks pay to borrow sterling overnight from other financial institutions and other institutional investors. Legal Entity [Axis] Legal Entity [Axis] Contracts in progress Inventory for Long-Term Contracts or Programs, Gross Residential Hospice Illinois [Member] Residential Hospice Illinois [Member] Residential Hospice Illinois [Member] Total partners’ capital Partners' Capital Geographical [Axis] Geographical [Axis] Options outstanding exercisable in 2024 (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Two Options outstanding exercisable in year two. Noncurrent liability Liability, Defined Benefit Plan, Noncurrent Special termination benefits Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits Percentage of interest acquired Business Acquisition, Percentage of Voting Interests Acquired After June 30, 2027 [Member] After June 30, 2027 [Member] Period of time after June 30, 2027 for which the TOSA term applies Options unvested, average exercise price (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Nonvested Weighted Average Exercise Price The weighted average price as of the end of the year at which grantees can acquire the shares reserved for issuance under the stock option plan which are not vested. Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Number of shares authorized to be repurchased remaining under previous authorization StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchasedUnderPreviousAuthorization Number of shares authorized to be repurchased remaining under previous authorization. Truist Floor Plan Facility [Member] Truist Floor Plan Facility [Member] Truist Floor Plan Facility Preferred Stock, Shares Issued Preferred Stock, Shares Issued Transferred at Point in Time [Member] Transferred at Point in Time [Member] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] 2025 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Return of investment in equity affiliates Proceeds from Equity Method Investment, Distribution, Return of Capital Amount Borrowed to Finance Business Acquisition Amount Borrowed to Finance Business Acquisition Amount Borrowed to Finance Business Acquisition Segments [Axis] Segments [Axis] Segments [Axis] Debt Debt Disclosure [Text Block] Pension and other postretirement plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract] Product and Service [Domain] Product and Service [Domain] Current and noncurrent lease liabilities Business Combination, Recognized Identifiable Asset Acquired and Liabiity Assumed, Current and Noncurrent Lease Liabilities Amount of current and noncurrent lease liabilities assumed in business combination Entity Shell Company Entity Shell Company Class B Common Stock [Member] Common Class B [Member] Common Class B [Member] Valuation allowance against the deferred tax assets recorded for the tax losses carryforward Deferred Tax Asset Operating Losses And Prior Stock Acquisitions Carryforward Valuation Allowance Valuation allowance against the deferred tax assets recorded for the tax losses carryforward. Capital Contributor [Domain] Capital Contributor [Domain] [Domain] for Capital Contributor [Axis] Concentration In Single Entity, Type Of Industry, Foreign Country Or Individual Fund [Member] Concentration In Single Entity, Type Of Industry, Foreign Country Or Individual Fund [Member] Concentration In Single Entity, Type Of Industry, Foreign Country Or Individual Fund [Member] Decrease related to prior year tax positions Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Allocation of the Assets of the Company's Pension Plans Schedule of Allocation of Plan Assets [Table Text Block] Non-U.S., Total Foreign Income Tax Expense (Benefit), Continuing Operations Operating lease payments due in 2023 Lessee, Operating Lease, Liability, to be Paid, Year One SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Consolidation Items [Domain] Consolidation Items [Domain] Subsequent Event [Member] Subsequent Event [Member] Document Period End Date Document Period End Date Percentage of Shares Eligible to be Redeemed Percentage of Shares Eligible to be Redeemed Percentage of share minority shareholders may put to the Company through redeemable noncontrolling interest Weiss [Member] Weiss [Member] Weiss Capital Contributor [Axis] Capital Contributor [Axis] Capital Contributor [Axis] Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items] Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] Summary of Changes in Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Total Assets Assets Amortization of net prior service cost included in net income Amortization of prior service credit (cost) Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax Mandatorily redeemable noncontrolling interest Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Fair Value of Shares Per Share Information Attributable to Graham Holdings Company Common Stockholders Earnings Per Share [Abstract] Small Business Small Business [Member] Small Business Medicare Accelerated Advanced Payment Program Relief Fund [Member] Medicare Accelerated Advanced Payment Program Relief Fund [Member] Medicare Accelerated Advanced Payment Program Relief Fund under the CARES Act Schedule of Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Axis] Schedule of Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Axis] Marketable equity securities Total Fair Value Equity Securities, FV-NI, Current Shares, Issued Shares, Issued Interest Rate Swap maturing in 2031 - $24.75 million [Member] Interest Rate Swap [Member] Schedule of Accounts Payable and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Exercised, Average Option Price (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Operating lease payments due in 2027 Lessee, Operating Lease, Liability, to be Paid, Year Five Amount of Revenue Recognized From Provider Relief Fund Amount of Revenue Recognized From Provider Relief Fund Amount of revenue recognized from provider relief fund Accrued compensation and related benefits Employee-related Liabilities, Current Net change in unrealized (depreciation) appreciation on investments Change in unrealized appreciation on investments The increase (decrease) resulting in a gain, in the difference between the fair value and the carrying value, or in the comparative fair values, of investments held at each balance sheet date, that was included in earnings for the period. Income Before Income Taxes Income Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Segment [Domain] Segments [Domain] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Fair value of company common stock (in dollars per share) Fair Value Of Company Common Stock Fair value of company common stock Goodwill, beginning balance Goodwill, ending balance Goodwill, Gross Accrued Compensation and Related Benefits Deferred Compensation Liability, Classified, Noncurrent Schedule of Investments [Line Items] Schedule of Investments [Line Items] Comprehensive (Loss) Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Award Type [Domain] Award Type [Domain] Grantee Status [Axis] Grantee Status [Axis] Income taxes receivable/payable Increase (Decrease) in Income Taxes Income taxes receivable Income Taxes Receivable, Current Cable ONE [Member] Cable One [Member] Cable One Share awards outstanding, restriction will lapse in 2027 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year Six Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year Six Investments in marketable equity securities Marketable Securities [Table Text Block] Cash flow hedges AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax Inventory Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Foreign currency exchange rate changes Goodwill, Foreign Currency Translation Gain (Loss) Foreign Currency Translation Adjustment [Member] Foreign Currency Translation Adjustments [Member] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Student and Customer Relationships [Member] Customer Relationships [Member] Entity Address, City or Town Entity Address, City or Town Ford auto dealership [Member] Ford auto dealership [Member] Ford auto dealership [Member] Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Percentage of Contributed Capital Percentage of Contributed Capital Percentage of Contributed Capital Short-term and month-to-month lease cost Short Term and Month to Month Lease Cost Amount of short-term lease cost, including expense for lease with term of one month or less. Goodwill impairments Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount Issuance of Class B common stock, net of restricted stock award forfeitures Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Intersegment Elimination [Member] Intersegment Eliminations [Member] Revenue Recognition, Maximum Period between Recognition of Revenue and Receipt of Payment Revenue Recognition, Maximum Period between Recognition of Revenue and Receipt of Payment Revenue Recognition, Maximum Period between Recognition of Revenue and Receipt of Payment 2028-2032 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Lessee, Operating Lease, Renewal or Termination Option Term Lessee, Operating Lease, Renewal or Termination Option Term Term of lessee's option to renew or terminate an operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Noncontrolling Interests Stockholders' Equity Attributable to Noncontrolling Interest Restricted cash Restricted Cash and Cash Equivalents, Current Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Interest accrued related to unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Accrued Raw materials Inventory, Raw Materials, Net of Reserves Supplemental Cash Flow And Balance Sheet Information Related To Operating Leases Schedule Of Supplemental Cash Flow And Balance Sheet Information Related To Leases [Table Text Block] Schedule Of Supplemental Cash Flow And Balance Sheet Information Related To Leases Unamortized debt issuance costs Debt Issuance Costs, Net Deferred tax assets with respect to non U.S. income tax loss carryforwards Non-U.S. income tax loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, Foreign Benefit Obligation [Member] Benefit Obligation [Member] Benefit obligation assumptions. Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Auditor Name Auditor Name Pension Plans [Member] Pension Plan [Member] Pension Plan [Member] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Acquisition-related costs Business Acquisition, Transaction Costs Reclassification from AOCI, Current Period, Tax Provision for income taxes Reclassification from AOCI, Current Period, Tax Identifiable Assets Identifiable Assets Identifiable assets by segment are those assets used in the Company's operations in each business segment. Leasehold improvements Leasehold Improvements, Gross Increases related to prior year tax positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Fair Value Measured at Net Asset Value Per Share [Member] Fair Value Measured at Net Asset Value Per Share [Member] Foreign assets Entity Wide Disclosure On Geographic Areas Long-Lived Assets Excluding Goodwill And Other Intangible Assets In Foreign Countries Amount of long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets, goodwill, and other intangible assets located in foreign countries in total in which the entity holds assets. Contingent consideration fair value measurements and accretion Accretion Expense Credit loss expense and provision for other receivables Credit Loss Expense and Provision For Other Receivables The amounts of credit loss expense and provision for other receivables. Price-Based Price-Based [Member] Price-Based Issuance of noncontrolling interest Proceeds from Contributed Capital Net sales Revenues State and Local, Deferred Deferred State and Local Income Tax Expense (Benefit) Health Care [Member] Health Care [Member] Amortization of intangible assets Amortization of Intangible Assets Amortization of Intangible Assets Liquidation Period [Domain] Liquidation Period [Domain] [Domain] for Liquidation Period [Axis] Changes in Carrying Amount of Goodwill Schedule of Goodwill [Table Text Block] Interest Interest Paid, Excluding Capitalized Interest, Operating Activities International equities [Member] Defined Benefit Plan, Equity Securities, Non-US [Member] Diplomas [Member] Diplomas [Member] Diplomas Post-Age 65 [Member] Post Age 65 [Member] Post Age 65 [Member] Operating lease payments due in 2025 Lessee, Operating Lease, Liability, to be Paid, Year Three Total Debt Debt, Long-Term and Short-Term, Combined Amount Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Contingent consideration fair value measurements and accretion Fair Value Measurements and Accretion Amount recognized for the remeasurement of fair value and the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations. Pension and Other Postretirement Plans [Member] Unrealized Gain (Loss) on Pensions and Other Postretirement Plans [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Inventories and Contracts in Progress Inventory, Policy [Policy Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Counterparty Name [Domain] Counterparty Name [Domain] Treasury Stock [Member] Treasury Stock [Member] Total Common Stockholders’ Equity Stockholders' Equity Attributable to Parent Finance lease payments due in 2025 Finance Lease, Liability, Payments, Due in Rolling Year Three Carryforward amount Tax Credit Carryforward, Amount Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Forfeited, Average Grant-Date Fair Value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Dividends paid on common stock Dividends, Common Stock JacksonvilleFL [Member] JacksonvilleFL [Member] JacksonvilleFL [Member] Income tax credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards Liquidation Period [Axis] Liquidation Period [Axis] Liquidation Period [Axis] Pension and other post retirement benefits liabilities Pension and other post retirement benefits liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Pension and Other Post Retirement Benefits Liabilities Amount of pension and postretirement liabilities assumed at the acquisition date. Costs amortized during the period Capitalized Contract Cost, Amortization Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Purdue University Global Final Payment Note Duration Purdue University Global Final Payment Note Duration Duration of note for final payment made by Purdue University Global to Kaplan upon termination of TOSA Estimated amortization of intangible assets, 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Three Applied Behavior Analysis clinics Applied Behavior Analysis clinics [Member] Applied Behavior Analysis clinics Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Retained Earnings [Member] Retained Earnings [Member] Add: Dividends paid–common stock outstanding Dividends, Common Stock, Cash Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Interest rate swap Interest Rate Cash Flow Hedge Asset at Fair Value Capital loss carryforward [Member] Capital Loss Carryforward [Member] Common Stock [Member] Common Stock [Member] Money market investments Money Market Funds, at Carrying Value Pinnacle Bank Line Of Credit maturing in 2023 [Member] Pinnacle Bank Line Of Credit [Member] Pinnacle Bank line of credit [Member] Number of reportable segments Number of Reportable Segments Components of Operating Lease Expense Lease, Cost [Table Text Block] Shares available for future awards Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Business Combination, Contingent Consideration, Liability Contingent consideration liabilities Business Combination, Contingent Consideration, Liability Share-Based Compensation Arrangement by Share-Based Payment Award, Award other than Options, Grants in Periods, Grante Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Award other than Options, Grants in Periods, Grante Date Fair Value The grant-date fair value of stock awards granted during the reporting period as calculated by applying the disclosed pricing methodology. First Five Years of Transition and Operations Support Agreement First Five Years of Transition and Operations Support Agreement First five years of TOSA Number of business lines Number of Business Lines The number of business lines. Statement [Table] Statement [Table] Vested, Average Grant-Date Fair Value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Gain on sale of investment in affiliate Gain on sale of investment in affiliates Equity Method Investment, Realized Gain (Loss) on Disposal Education Code3 And Decile [Member] Education Code3 And Decile [Member] Education, Code3 and Decile 5.75% Unsecured Notes maturing in 2026 [Member] Five Point Seven Five Percent Unsecured Notes due June 1, 2026 [Member] Five Point Seven Five Percent Unsecured Notes due June 1, 2026 [Member] Lease Liabilities Noncurrent lease liabilities Operating Lease, Liability, Noncurrent Supplemental Cash Flow And Balance Sheet Information Related To Financing Leases Supplemental Cash Flow And Balance Sheet Information Related To Financing Leases [Table Text Block] Supplemental Cash Flow And Balance Sheet Information Related To Financing Leases Expense associated with the retirement benefits provided under incentive savings plans Defined Contribution Plan, Cost Statistical Measurement [Axis] Statistical Measurement [Axis] Shares repurchased by company Treasury Stock, Shares, Acquired 2012 Incentive Compensation Plan [Member] 2012 Incentive Compensation Plan [Member] 2012 Incentive Compensation Plan which authorizes the awarding of Class B common stock to key employees in the form of stock awards, stock options and other awards involving the actual transfer of shares. [Member] Deferred payments of acquisitions Payment for Contingent Consideration Liability, Financing Activities Other Comprehensive (Loss) Income, Before Tax Other Comprehensive Income (Loss), Before Tax Other Comprehensive Income (Loss), before Tax Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Indefinite-Lived Intangible Assets Net Carrying Amount Indefinite-Lived Intangible Assets (Excluding Goodwill) Grantee Status [Domain] Grantee Status [Domain] Other Other Operating Activities, Cash Flow Statement Receivables from contracts with customers, less estimated credit losses Accounts Receivable, after Allowance for Credit Loss, Current Purchases of marketable equity securities Payments to acquire marketable securities Payments to Acquire Marketable Securities Equity Components [Axis] Equity Components [Axis] Equity Components [Axis] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Proceeds from sale of noncontrolling interest Proceeds from Noncontrolling Interests Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Restatement [Domain] Revision of Prior Period [Domain] UNITED KINGDOM UNITED KINGDOM Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Statement [Line Items] Statement [Line Items] Accounts Receivable Accounts Payable And Accrued Liabilities [Abstract] Accounts Receivable Accounts Payable And Accrued Liabilities [Abstract] -- None. No documentation exists for this element. -- Equity in earnings of affiliates, net of distributions Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Shares subject to award outstanding Beginning of year, unvested, Number of Shares End of year, unvested, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Variable Rate [Domain] Variable Rate [Domain] Percentage of Cost Efficiencies Percentage of Cost Efficiencies Percentage of Cost Efficiencies to be used to Calculate Additional Efficiency Payment Accumulated other comprehensive income, net of taxes Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Selling, General and Administrative Expense Selling, General and Administrative Expense Deferred Revenue Deferred Revenue Number of Performance Obligations In Contract With Tuition Cap Number of Performance Obligations In Contract With Tuition Cap Number of Performance Obligations In Contract With Tuition Cap Lease Right-of-Use Assets Lease right-of-use assets Operating Lease, Right-of-Use Asset AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Right to elect Board of Directors percentage Right To Elect Board Of Directors Percentage Right To Elect Board Of Directors Percentage Deferred revenue recognized in period related to beginning balance Deferred Revenue, Revenue Recognized Auditor Firm ID Auditor Firm ID Fair value of redeemable noncontrolling interest acquired Business Combination Acquisition Of Less than 100 Percent Redeemable Noncontrolling Interest Fair Value This element represents the fair value of the redeemable noncontrolling interest in the acquiree at the acquisition date. Current finance lease liability Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] CSI Pharmarcy [Member] CSI Pharmarcy [Member] CSI Pharmarcy [Member] Document Transition Report Document Transition Report 2024 Defined Benefit Plan, Expected Future Benefit Payment, Year Two non-U.S. [Member] Foreign Tax Authority [Member] Local Phone Number Local Phone Number Activity Related to Stock Options Share-Based Payment Arrangement, Option, Activity [Table Text Block] Income from Operations Income (Loss) from Operations Operating Income (Loss) Percentage of Revenue Remaining To Be Paid Percentage of Revenue Remaining To Be Paid Percentage of Purdue University Global Revenue remaining after Kaplan Efficiency Payment and other adjustments paid to Purdue University Global Disposal Group, Not Discontinued Operation, Operating Income Disposal Group, Not Discontinued Operation, Operating Income (Loss) Amount of operating income (loss) attributable to disposal group. Excludes discontinued operations. U.S. fixed income [Member] Fixed Income Securities, US [Member] Investment that provides a return in the form of fixed periodic payments and eventual return of principal at maturity, domiciled in United States of America (US). Deferred tax assets with respect to U.S. Federal income tax loss carryforwards U.S. Federal income tax loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, Domestic Recently Adopted and Issued Accounting Pronouncemets New Accounting Pronouncements, Policy [Policy Text Block] Income Taxes [Table] Income Taxes [Table] -- None. No documentation exists for this element. -- Operating Entity Investment [Member] Operating Entity Investment [Member] Operating Entity Investment Other Comprehensive Income (Loss) [Table] Other Comprehensive Income (Loss) [Table] Other Comprehensive Income (Loss) [Table] State [Member] State and Local Jurisdiction [Member] Pensions and Other Postretirement Benefits Pension and Other Postretirement Plans, Pensions, Policy [Policy Text Block] Services [Member] Service [Member] Goodwill and Intangible Asset Impairment Goodwill and Intangible Asset Impairment Schedule of Non-Operating Income (Expense) [Table] Schedule of Non-Operating Income (Expense) [Table] Schedule of Non-Operating Income (Expense) [Table] Recipient of Consideration [Domain] Recipient of Consideration [Domain] [Domain] for Recipient of Consideration Amortization of net actuarial (gain) loss included in net income Recognized net actuarial gain (loss) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Loan Receivable, Payment Term Loan Receivable, Payment Terms Description of the payment terms of the debt instrument (for example whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment. Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Cash balance interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate Property, plant and equipment, net Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Net Prior Service Cost [Member] Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Operating lease payments due in 2026 Lessee, Operating Lease, Liability, to be Paid, Year Four Income Statement [Abstract] Income Statement [Abstract] Exercise Price Range of $805-$872 [Member] Price Range Four [Member] Exercise Price of $805-872 Number of shares granted Granted, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross U.S. Federal, Deferred Deferred Federal Income Tax Expense (Benefit) Capital in Excess of Par Value [Member] Additional Paid-in Capital [Member] Document Fiscal Period Focus Document Fiscal Period Focus After 2027 [Member] Loss Carryforwards Expirations Range Two [Member] -- None. No documentation exists for this element. -- Cumulative Effect, Period of Adoption, Adjusted Balance Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Restricted Cash, Noncurrent Restricted Cash, Noncurrent Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Prepaid pension cost Deferred Tax Liabilities, Prepaid Expenses Retransmission Revenue [Member] Retransmission Revenue [Member] Retransmission Revenue [Member] Cash and Cash Equivalents Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] Heverald [Member] Heverald [Member] Heverald [Member] Diluted average number of common shares outstanding (in shares) Denominator for diluted earnings per share (shares) Weighted Average Number of Shares Outstanding, Diluted Volatility, minimum (percentage) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Schedule of Inventories and Contracts in Progress Schedule of Inventory, Current [Table Text Block] Expected life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Network affiliation agreements [Member] Contract-Based Intangible Assets [Member] ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Licensure and Accreditation [Member] Licensure and Accreditation [Member] Licensure And Accreditation [Member] Alphabet And Berkshire Hathaway Common Stock [Member] Alphabet And Berkshire Hathaway Common Stock [Member] Alphabet and Berkshire Hathaway Common Stock [Member] Kaplan Stock Option [Member] Kaplan Stock Option [Member] -- None. No documentation exists for this element. -- Kaplan International [Member] Kaplan International [Member] Kaplan International [Member] Awarded, Average Grant-Date Fair Value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Revenue Source [Domain] Revenue Source [Domain] [Domain] for Revenue Source [Axis} Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Operating Segments [Member] Operating Segments [Member] Deferred income tax asset Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Percent of Plan Assets Managed Internally by Company Percent of Plan Assets Managed Internally by Company The percentage of plan assets managed internally by the Company. Intrinsic value of options exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Gain on acquiring a controlling interest in an equity affiliate Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Deferred tax liability (asset) Defined Benefit Plan Accumulated Other Comprehensive Income Tax Tax recorded on the defined benefit plan accumulated other comprehensive income. Impairment of intangible assets Impairment of Intangible Assets, Finite-Lived Number of shares held in investment Investment Owned, Balance, Shares Information related to a Disposal Group Schedule Of Disposal Groups Excluding Discontinued Operations Income Statement Balance Sheet And Additional Disclosures [Table Text Block] Tabular disclosure of information related to a disposal group. Excludes a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component. Percentage of Revenue Percentage of Revenue from Contract with Customer, Excluding Assessed Tax Percentage of Revenue Recognized During Period from Contract with Customer, Excluding Assessed Tax Net (income) loss attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Contingencies and Other Commitments Commitments and Contingencies Disclosure [Text Block] Accumulated impairment losses, beginning balance Accumulated impairment losses, ending balance Goodwill, Impaired, Accumulated Impairment Loss Single Equity Concentration [Member] Single Equity Concentration [Member] Information about an entity's defined benefit plan's significant investment concentrations in either a single entity, type of industry, foreign country and/or individual fund. Numerator for basic earnings per share Net Income (Loss) Available to Common Stockholders, Basic Summarized Financial Data of Nonconsolidated Affiliates Equity Method Investments [Table Text Block] Common Stock, Shares, Issued Common Stock, Shares, Issued Antidilutive Restricted Stock Antidilutive Restricted Stock Additional shares excluded in the calculation of diluted EPS as a result of the antidilutive effect of restricted stock using the treasury stock method. Investments in Affiliates Equity Method Investments Ultimate cash balance interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Ultimate Weighted-Average Interest Crediting Rate Ultimate weighted-average interest crediting rate used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate. Foreign exchange loss Foreign currency loss, net Foreign Currency Transaction Gain (Loss), before Tax Options outstanding exercisable now Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Now Options outstanding exercisable now. Capitalized Contract Cost Capitalized Contract Cost [Table Text Block] Gross unrealized losses EquitySecuritiesFVNIAccumulatedGrossUnrealizedLoss Amount of unrealized loss on investment on equity security measured at fair value with change in fair value recognized in net income (FV-NI). March 22, 2018 through June 30, 2022 [Member] March 22, 2018 through June 30, 2022 [Member] Period of time March 22, 2018 through June 30, 2022 for which the TOSA term applies (first 4 years) Transferred over Time [Member] Transferred over Time [Member] Finance Lease, Liability, Current Finance Lease, Liability, Current Net Cash (Used in) Provided by Investing Activities Net Cash Provided by (Used in) Investing Activities Debt instrument, face amount Debt Instrument, Face Amount Markel Corporation [Member] MarkelCorporation [Member] Markel Corporation [Member] Investments in Equity Securities Investment, Policy [Policy Text Block] Defined Benefit Plans [Member] Defined Benefit Plans [Member] Defined benefit plans consisting of various pension plans and a Supplemental Executive Retirement Plan (SERP). Total Comprehensive (Loss) Income Attributable to Graham Holdings Company Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net loss (gain) on sales and disposition of businesses Net Gain Loss On Sales And Disposition of Businesses Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment. Summary of Segment Reporting Information, by Operating Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Entity Current Reporting Status Entity Current Reporting Status Schedule of Obligation, Asset and Funding Information Schedule of Net Funded Status [Table Text Block] Finance lease payments due in 2023 Finance Lease, Liability, to be Paid, Year One Property, plant and equipment impairment charges Property, plant and equipment Tangible Asset Impairment Charges Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Contract with Customer, Duration [Axis] Contract with Customer, Duration [Axis] Operating lease impairment Lease right-of-use assets Operating Lease, Impairment Loss Long-term Contract with Customer [Member] Long-Term Contract with Customer [Member] Additions - Charged to Costs and Expenses SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Schedule of assets acquired and liabilities assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Stock options outstanding Beginning, Number of Shares End, Number of Shares Options Outstanding, Shares Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Ford Floor Plan Facility [Member] Ford Floor Plan Facility [Member] Ford Floor Plan Facility Other Stockholders' Equity, Other Bachelors [Member] Bachelors [Member] Bachelors Liabilities Liabilities [Abstract] Equity Method Investment, Diluted Ownership Percentage Equity Method Investment, Diluted Ownership Percentage Equity Method Investment, Diluted Ownership Percentage Investments in Marketable Securities Investments in Marketable Securities Amount of investment for purchase of marketable security. Effect of Currency Exchange Rate Change Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Property, Plant and Equipment, Net Property, plant and equipment, net Property, Plant and Equipment, Net Title of Individual with Relationship to Entity [Domain] Title of Individual [Domain] Number of contingently issuable shares Number of contingently issuable shares Number of contingently issuable shares in stock award Redeemable Noncontrolling Interest Redeemable noncontrolling interest Redeemable Noncontrolling Interest, Equity, Other, Fair Value Group of Senior Managers of GHG [Member] Group of Senior Managers of GHG [Member] Group of Senior Managers of GHG [Member] Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Tax loss carryforwards subject to expiration Operating Losses And Prior Stock Acqusitions Carryforward Subject To Expiration Tax loss carryforward resulting from operating losses and prior stock acquisitions subject to expiration. Databases and Technology [Member] Database Rights [Member] Other Comprehensive Income (Loss) [Line Items] Other Comprehensive Income (Loss) [Line Items] [Line Items] for Other Comprehensive Income (Loss) [Table] Noncurrent finance lease liability Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Number of shares forfeited due to modification Forfeited, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Other income, net Total Other Non-Operating Income Other income, net Other Nonoperating Income (Expense) Balance Sheet Location [Axis] Balance Sheet Location [Axis] Graham Holdings Company [Member] Graham Holdings Company [Member] Graham Holdings Company [Member] Tax Credit Carryforward, Valuation Allowance Tax Credit Carryforward, Valuation Allowance Year that rate reaches ultimate trend rate Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate Number of investments the company's pension plan held which individually exceed 10% of total plan assets Number Of Investments Companys Pension Plan Held Which Individually Exceed 10 Percent Of Total Plan Assets Number Of Investments The Companys Pension Plan Held Which Individually Exceed 10 Percent Of Total Plan Assets Class A Common Stock [Member] Common Class A [Member] Expected return on plan assets (percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets Curtailment Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment Defined Benefit Plan Assets Total [Member] Defined Benefit Plan Assets Total [Member] -- None. No documentation exists for this element. -- Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Share-based Payment Arrangement [Member] Share-Based Payment Arrangement [Member] Rent expense for operating leases Operating Leases, Rent Expense Total Current Assets Current assets Assets, Current Accelerated Depreciation Accelerated Depreciation Amount of accelerated depreciation charged against earnings. Special separation benefit expense Non-operating pension and postretirement benefit income, net Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits Income taxes Income Taxes Paid, Net Intersubsegment Eliminations [Member] Intersubsegment Eliminations [Member] Entity Small Business Entity Small Business Amortization of lease right-of-use asset Operating Lease, Right-of-Use Asset, Amortization Expense Dividends declared per common share Common Stock, Dividends, Per Share, Declared Contract with Customer, Duration [Domain] Contract with Customer, Duration [Domain] Number of multiemployer plans contributed to Number Of Multiemployer Plans Contributed To Number of multiemployer pension plans to which the Company contributed. Number of Consecutive Years of Purdue University Global Cash Operating Losses Number of Consecutive Years of Purdue University Global Cash Operating Losses Number of consecutive years of Purdue University Global cash operating losses for option to terminate Transition and Operations Support Agreement Amortized Intangible Assets, Net Net Carrying Amount Finite-Lived Intangible Assets, Net Distribution to noncontrolling interest Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Fair Value, Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Tax benefit from stock option exercises Share-Based Payment Arrangement, Exercise of Option, Tax Benefit Total unrecognized compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Exercise Price $427 [Member] Price Range Two [Member] Exercise Price of $325 Investments in securities, at estimated fair value Investments in securities, at estimated fair value Amount of investments in securities measured at fair value Capital Stock, Stock Awards And Stock Options Capital Stock, Stock Awards And Stock Options [Text Block] -- None. No documentation exists for this element. -- N2K Networks [Member] N2K Networks [Member] N2K Networks Supplemental Education [Member] Supplemental Education [Member] Supplemental Education Intrinsic value of options outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Concentration in single marketable equity security [Member] Concentration in single marketable equity security [Member] Concentration in single marketable equity security Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Intrinsic value of options unvested Share Based Compensation Arrangement By Share Based Payment Award Options Unvested Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Unvested Intrinsic Value Deferred Revenue [Domain] Deferred Revenue [Domain] Change in capitalized contract cost, other Change in Capitalized Contract Cost, Other Change in capitalized contract cost, other U.S. Federal, Total Federal Income Tax Expense (Benefit), Continuing Operations Unsecured notes Unsecured Debt Total Operating Costs and Expenses Costs and Expenses Defined Benefit Plan Health Care Cost Trend Groups [Axis] Defined Benefit Plan Health Care Cost Trend Groups [Axis] Defined Benefit Plan Health Care Cost Trend Groups [Axis] Debt Instrument [Line Items] Debt Instrument [Line Items] Investment Managers [Domain] Investment Managers [Domain] [Domain] for Investment Managers [Axis] number of performance obligations with variable consideration number of performance obligations with variable consideration number of performance obligations with variable consideration Supplemental Education [Member] Test Preparation [Member] Test Preparation [Member] Operating Lease, Liability Total operating lease liability Operating Lease, Liability Land Land Balance at Beginning of Period Balance at End of Period SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Equity-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Finance Lease, Liability, to be Paid Finance Lease, Liability, to be Paid Finance Lease, Liability, Fiscal Year Maturity Finance Lease, Liability, Fiscal Year Maturity [Table Text Block] Ultimate health care cost trend rate Defined Benefit Plan, Ultimate Health Care Cost Trend Rate 2028 and after [Member] Loss Carry Forwards Expirations After Year Five [Member] Loss Carry Forwards Expirations After Year Five Member Retirement Benefits, Description [Abstract] Retirement Benefits, Description [Abstract] Manufacturing [Member] Manufacturing [Member] Manufacturing business Short-term investment funds [Member] Fixed Income Funds [Member] Estimated amortization of intangible assets, 2024 Finite-Lived Intangible Asset, Expected Amortization, Year Two Granted, Average Option Price (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Subsegments [Domain] Subsegments [Domain] Benefits paid Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Monte Carlo Monte Carlo [Member] Monte Carlo Total Assets [Member] Assets, Total [Member] Changes in fair value Fair​ Value, ​Measurement​ With ​Unobservable ​Inputs ​Reconciliations, ​Recurring ​Basis, ​Liability​, Gain (Loss), Changes in Fair Value Amount of gain (loss) recognized in income due to changes in fair value from liability measured at fair value on recurring basis using unobservable input (level 3). Borrowing capacity Vehicle Floor Plan Facility Borrowing Capacity The aggregate borrowing capacity under the vehicle floor plan facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facilities. Net borrowings under revolving credit facilities Proceeds from (Repayments of) Lines of Credit Total Restructuring Costs Included in Segment Results Restructuring Charges Unrealized gain on marketable equity securities Deferred Tax Liabilities, Unrealized Gains on Marketable Equity Securities Amount of deferred tax liability attributable to taxable temporary differences from unrealized gains on marketable equity securities. Auditor Location Auditor Location Organization and Nature of Operations Nature of Operations [Text Block] Other Temporary Equity, Other Changes Entity Filer Category Entity Filer Category Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest [Table Text Block] Common Stockholders’ Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] U.S. Federal, Current Current Federal Tax Expense (Benefit) U.S. [Member] UNITED STATES Operating income of acquired companies since acquisition date Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract] Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract] Stock-based compensation expense (credit) Share-Based Payment Arrangement, Expense Commitments and Contingencies (Note 18) Commitments and Contingencies Security Exchange Name Security Exchange Name Beginning, Average Option Price (in dollars per share) End, Average Option Price (in dollars per share) Options Outstanding, Weighted Average Exercise Price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Deferred Income Tax Liabilities [Line Items] Deferred Income Tax Liabilities [Line Items] [Line Items] for Deferred Income Tax Liabilities [Table] Defined Benefit Plans Disclosures Defined Benefit Plans Assumption [Domain] Defined Benefit Plans Disclosures Defined Benefit Plans Assumption [Domain] Defined Benefit Plans Disclosures Defined Benefit Plans Assumption [Domain] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Operating Revenues Revenue from Contract with Customer, Excluding Assessed Tax Early Retirment Program Expense [Axis] Early Retirment Program Expense [Axis] -- None. No documentation exists for this element. -- Service cost Pension service cost Defined Benefit Plan, Service Cost Deferred Tax Valuation Allowance [Member] SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] Shares reserved for issuance Common Stock, Capital Shares Reserved for Future Issuance Dividends [Domain] Dividends [Domain] Cover [Abstract] Cover [Abstract] Cash balance interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Weighted-Average Interest Crediting Rate Entity Voluntary Filers Entity Voluntary Filers Goodwill, Impairment Loss Impairment Goodwill, Impairment Loss Deferred tax assets with respect to U.S. Federal foreign tax credit carryforwards U.S Federal foreign income tax credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards, Foreign non-employee Director non-employee Director [Member] non-employee Director Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Net Actuarial Loss [Member] Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Finance Lease, Weighted Average Discount Rate, Percent Finance Lease, Weighted Average Discount Rate, Percent Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Segment Reporting [Abstract] Segment Reporting [Abstract] Commercial note with Truist Bank maturing in 2032 - $71.6 million [Member] Commercial note with Truist Bank maturing in 2032 - $71.6 million [Member] Commercial note with Truist Bank maturing in 2032 - $71.6 million Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Stock Compensation Liabilities Assumed Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Stock Compensation Liabilities Assumed Value of liabilities assumed at the acquisition date related to acquiree's stock compensation plan Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Investments [Domain] Investments [Domain] Defined Benefit Plan by Plan Asset Categories [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Documents Incorporated by Reference [Text Block] Documents Incorporated by Reference [Text Block] Recognized actuarial loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) Discount rate to determine benefit obligation Discount rate (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Total Liabilities and Equity Liabilities and Equity Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Non U.S. [Member] Non-US [Member] Deferred tax assets Deferred Tax Assets, Gross Schedule of Income Before Income Taxes, Domestic and Foreign Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Noncontrolling interest Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value Share awards outstanding, restriction will lapse in 2027 Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Five Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercisable Year Five Joyce/Dayton Corp. [Member] Joyce/Dayton Corp. [Member] Joyce/Dayton Corp. [Member] Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Numerator for diluted earnings per share Net Income (Loss) Available to Common Stockholders, Diluted Diluted net income per common share (in USD per share) Earnings Per Share, Diluted (in usd per share) Earnings Per Share, Diluted Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Trade Names and Trademarks [Member] Trademarks and Trade Names [Member] Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Parent Consolidation Items [Axis] Consolidation Items [Axis] Net gain on cost method investments Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount Exercise Price Range [Domain] Exercise Price Range [Domain] CARES Act relief from COVID-19 [Member] CARES Act relief from COVID-19 [Member] CARES Act relief from COVID-19 Net proceeds from (repayments of) vehicle floor plan payable Proceeds From (Payments Of) Vehicle Floor Plan Payable Net The net cash inflow or cash outflow from proceeds or repayment of the vehicle floor plan payable. Operating lease payments due in 2024 Lessee, Operating Lease, Liability, to be Paid, Year Two Other current assets Other Assets, Current Irrevocable Group Annuity Contract Purchase [Member] Irrevocable Group Annuity Contract Purchase [Member] Irrevocable Group Annuity Contract Purchase [Member] Transaction [Axis] Transaction [Axis] Transaction [Axis] Beginning unrecognized tax benefits Ending unrecognized tax benefits Unrecognized Tax Benefits Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance Equity securities [Member] Equity Securities [Member] U.S. Income (Loss) from Continuing Operations before Income Taxes, Domestic Cumulative Effect, Period of Adoption, Adjustment Cumulative Effect, Period of Adoption, Adjustment [Member] Discount rate to determine periodic cost Discount rate (percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Schedule of Changes in Estimated Credit Losses Accounts Receivable, Allowance for Credit Loss [Table Text Block] Other Comprehensive Income (Loss), before Reclassifications, before Tax Other Comprehensive Income (Loss), before Reclassifications, before Tax Commercial note with Truist Bank maturing in 2031 - $24.75 million [Member] Commercial note with Truist Bank maturing in 2031 - $24.75 million [Member] Commercial note with Truist Bank maturing in 2031 - $24.75 million Maturities of Operating Lease Liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Amount of Revenue Recognized From Government Relief, CARES Act Amount of Revenue Recognized From Advanced Payment Program Amount of Revenue Recognized From Advanced Payment Program Net proceeds from sales of businesses, property, plant and equipment and other assets Net Proceeds From Sale Of Businesses Property Plant And Equipment And Other Assets The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period. Also included is the cash inflow from the sale of long-lived, physical assets and other assets. Entity Address, Address Line One Entity Address, Address Line One Investment maturity length Investment Maturity Length For Classification As Cash And Cash Equivalents Investment maturity length for classification as cash and cash equivalents. Income tax benefit (expense) related to items of other comprehensive (loss) income Other Comprehensive Income (Loss), Income Tax Other Comprehensive Income (Loss), Tax Hoover Treated Wood Products [Member] Hoover Treated Wood Products [Member] Hoover Treated Wood Products [Member] Net loss (gain) on sales or write-downs of property, plant and equipment GainLossOnSaleOrWritedownOfPropertyPlantEquipment Amount of gain (loss) on sale, disposal or write-down of property, plant and equipment assets. Education Programs [Domain] Education Programs [Domain] Education Programs Product and Service [Axis] Product and Service [Axis] Class of Stock [Domain] Class of Stock [Domain] Expected return on assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Share awards outstanding, restriction will lapse in 2023 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year One Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Year Six Interest expense Interest expense Interest Expense Investments in Affiliates Equity Method Investments [Policy Text Block] Direction of change for assumed health care cost trend rate Defined Benefit Plan, Assumed Health Care Cost Trend Rate, Description Retirement Plan Type [Axis] Retirement Plan Type [Axis] Claims received Loss Contingency Borrower Defense Claims Received Number Number of claims received Inventories, Contracts in Progress and Vehicle Floor Plan Payable Inventory Disclosure [Text Block] Components of Debt Schedule of Long-Term Debt Instruments [Table Text Block] Machinery and Equipment [Member] Machinery and Equipment [Member] Leases Deferred Tax Liabilities, Leasing Arrangements Building [Member] Building [Member] Penalties accrued related to unrecognized tax benefits Unrecognized Tax Benefits, Income Tax Penalties Accrued Funded status Defined Benefit Plan, Funded (Unfunded) Status of Plan Equity Method Investment Impairment Equity Method Investment, Other than Temporary Impairment Berkshire Hathaway [Member] Berkshire Hathaway [Member] Berkshire Hathaway Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Market value of company's stock (in dollars per share) Common Stock Stated Market Value Per Share Common Stock Stated Market Value Per Share Contributions to multiemployer pension plans Multiemployer Plan, Employer Contribution, Cost Deferred tax liabilities Deferred Tax Liabilities, Gross Components of Financing Lease Expense [Member] Components of Financing Lease Expense [Table Text Block] Components of Financing Lease Expense Operating Revenues Revenue from Contract with Customer [Abstract] Non-compete Agreements [Member] Noncompete Agreements [Member] After June 30, 2024 [Member] After June 30, 2024 [Member] Period of time after June 30, 2024 (7th year and beyond) for which the TOSA term applies Weighted average interest rate Average annual interest rate of borrowings Debt Instrument, Interest Rate During Period Operating cash flows from finance leases Finance Lease, Interest Payment on Liability Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Cumulative Payments For Advance to Affiliate Cumulative Payments For Advance to Affiliate The cumulative cash outflow from advancing money to an affiliate (an entity that is related but not strictly controlled by the entity). Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Table] Disclosures pertaining to an entity's basic and diluted earnings per share. Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Estimated amortization of intangible assets, 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Five Measurement Frequency [Axis] Measurement Frequency [Axis] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Estimated Credit Losses [Member] SEC Schedule, 12-09, Allowance, Credit Loss [Member] CARES Act Fund [Domain] CARES Act Fund [Domain] CARES Act Fund After June 30, 2023 [Member] After June 30, 2023 [Member] Period of time after June 30, 2023 (6th year and beyond) for which the TOSA term applies Other accrued liabilities Other Accrued Liabilities, Current Number of shares authorized to be repurchased Stock Repurchase Program, Number of Shares Authorized to be Repurchased Foreign Investments [Member] Foreign Investments [Member] Information about the entity's defined pension plan foreign investments. Gross amount Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax CyberVista [Member] CyberVista [Member] CyberVista Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Options unvested, shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Dividends paid Payments of Ordinary Dividends Dividends [Axis] Dividends [Axis] U.S. Federal taxes at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Disposal Group, Not Discontinued Operation, Revenue Disposal Group, Not Discontinued Operation, Revenue Amount of revenue attributable to disposal group. Excludes discontinued operations. Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Authorized shares remaining for repurchase Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased (Loss) gain on marketable equity securities Gain (Loss) on Securities [Table Text Block] Private Equity Fund Investment [Member] Private Equity Fund Investment [Member] Private Equity Fund Investment Less: Imputed interest Finance Lease, Liability, Undiscounted Excess Amount Lease cost net of sublease income Total net lease cost Lease Cost Net of Sublease Income Amount of lease cost, net of sublease income, recognized by lessee for lease contract Percent Of Plan Assets Managed By Investment Companies Percent Of Plan Assets Managed By Investment Companies The percentage of plan assets managed by investment companies. Portion of 2022 investments in marketable equity securities that settled in January 2023 Portion of 2022 investments in marketable equity securities that settled in January 2023 Portion of 2022 investments in marketable equity securities that settled in January 2023 Impairment of goodwill and other long-lived assets Impairment of Long-Lived Assets Asset Impairment Charges Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Advances to Affiliate Advances to Affiliate Intersection [Member] Intersection [Member] Intersection Holdings,LLC [Member] Finance Lease, Variable Cost Finance Lease, Variable Cost Finance Lease, Variable Cost