Amount of Revenue Recognized From Advanced Payment Program

No definition available.

Name:	ghc_AmountOfRevenueRecognizedFromAdvancedPaymentProgram
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized from provider relief fund

+ References

No definition available.

+ Details

Name:	ghc_AmountOfRevenueRecognizedFromProviderReliefFund
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount received from the government as relief under the CARES Act

+ References

No definition available.

+ Details

Name:	ghc_GovernmentReliefCARESAct
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Minimum Term of Contract

+ References

No definition available.

+ Details

Name:	ghc_MinimumTermofContract
Namespace Prefix:	ghc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Revenue Recognized During Period from Contract with Customer, Excluding Assessed Tax

+ References

No definition available.

+ Details

Name:	ghc_PercentageofRevenuefromContractwithCustomerExcludingAssessedTax
Namespace Prefix:	ghc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue Remaining Performance Obligation Percentage of Revenue Expected to be Recognized Over Next 12 Months

+ References

No definition available.

+ Details

Name:	ghc_RevenueRemainingPerformanceObligationPercentageofRevenueExpectedtobeRecognizedOverNext12Months
Namespace Prefix:	ghc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126919976&loc=SL49130533-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=126919976&loc=SL49130531-203044

+ Details

Name:	us-gaap_ContractWithCustomerAssetNetNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredRevenueRevenueRecognized1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ghc_CARESActFundAxis=ghc_ProviderReliefFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ghc_GrahamHealthcareGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=ghc_CARESActReliefFromCOVID19Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ghc_CARESActFundAxis=ghc_MedicareAcceleratedAdvancedPaymentProgramReliefFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredOverTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredAtPointInTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=us-gaap_NonUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=ghc_KaplanInternationalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=ghc_TestPreparationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContractWithCustomerDurationAxis=us-gaap_LongTermContractWithCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Revenue from Contracts with Customers (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Jun. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Deferred revenue recognized in period related to beginning balance			$ 308.2
Provider Relief Fund [Member] \| Graham Healthcare Group [Member] \| CARES Act relief from COVID-19 [Member]
Disaggregation of Revenue [Line Items]
Government Relief, CARES Act		$ 7.4
Amount of Revenue Recognized From Provider Relief Fund					$ 5.7
Medicare Accelerated Advanced Payment Program Relief Fund [Member] \| Graham Healthcare Group [Member] \| CARES Act relief from COVID-19 [Member]
Disaggregation of Revenue [Line Items]
Government Relief, CARES Act	$ 31.5
Amount of Revenue Recognized From Government Relief, CARES Act			$ 12.6	$ 18.9
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Percentage of Revenue			58.00%	67.00%	73.00%
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Percentage of Revenue			42.00%	33.00%	27.00%
U.S. [Member]
Disaggregation of Revenue [Line Items]
Percentage of Revenue			81.00%	78.00%	78.00%
Non U.S. [Member]
Disaggregation of Revenue [Line Items]
Percentage of Revenue			19.00%	22.00%	22.00%
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, Net, Noncurrent			$ 26.3	$ 17.7
Supplemental Education [Member] \| Long-term Contract with Customer [Member]
Disaggregation of Revenue [Line Items]
Minimum Term of Contract			12 months
Revenue Remaining Performance Obligation Percentage of Revenue Expected to be Recognized Over Next 12 Months			68.00%