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

Amount of time investment had been in an unrealized loss position.

No definition available.

Name:	ghc_AmountOfTimeInvestmentInUnrealizedLossPosition
Namespace Prefix:	ghc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of unrealized gain (loss) on investments in equity securities classified as available-for-sale securities.

No definition available.

Name:	ghc_AvailableforsaleEquitySecuritiesNetUnrealizedGainLoss
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Unsecured short-term debt instrument issued by corporations which are highly liquid investments that are readily convertible to know amounts of cash and interest-bearing accounts that typically pay a higher interest rate and are FDIC insured.

No definition available.

Name:	ghc_CommercialPaperAndMoneyMarketInvestments
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of gross cash distributions received from an equity method investment.

No definition available.

Name:	ghc_EquityMethodInvestmentCashDistributions
Namespace Prefix:	ghc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting that was sold.

No definition available.

Name:	ghc_EquityMethodInvestmentOwnershipPercentageSold
Namespace Prefix:	ghc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

This item represents the total realized gain included in earnings for the period as a result of exchanging marketable securities.

No definition available.

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

Percentage of total fair value of the Company's investments in marketable equity securities.

No definition available.

Name:	ghc_MarketableSecuritiesEquitySecuritiesPercentageOfTotalMarketableSecuritiesEquitySecurities
Namespace Prefix:	ghc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Equity Method InvestmentShares Held In Investee Company

No definition available.

Name:	ghc_MarketableSecuritiesEquitySecuritiesSharesHeldInInvesteeCompany
Namespace Prefix:	ghc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Number Berkshire shares exchanged held by Graham Holdings Company and an amount of cash in exchange for Graham Holdings Company common stock held by Berkshire Hathaway.

No definition available.

Name:	ghc_NumberofBerkshireSharesExchanged
Namespace Prefix:	ghc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Percentage of the Company's common stock held by an investee company.

No definition available.

Name:	ghc_PercentageOfCommonStockHeldByInvesteeCompany
Namespace Prefix:	ghc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount of investments in equity securities and other forms of securities that provide ownership interests classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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

The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount of gain (loss) on sale or disposal of an equity method investment.

No definition available.

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

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.12)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 7

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

Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 13

-Paragraph Column C

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column E

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-12.Column C.3,4)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611133-123010

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 4

-Subparagraph (SX 210.12-12C.Column C.7)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611225-123010

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column E.2,3)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611322-123010

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 5

-Subparagraph (SX 210.12-13.Column C.6)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611282-123010

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph Column C

-Article 12

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph 3, 4

-Article 12

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph 2, 3

-Article 12

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 13

-Paragraph 6

-Article 12

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph 7

-Article 12

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph Column C

-Article 12

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

This item represents the total realized gain (loss) included in earnings for the period as a result of selling marketable securities categorized as trading, available-for-sale, or held-to-maturity.

No definition available.

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

This element represents the amount of loss recognized for other than temporary impairments (OTTI) of investments in debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.M)

-URI http://asc.fasb.org/extlink&oid=27011274&loc=d3e87990-122713

Name:	us-gaap_MarketableSecuritiesRealizedGainLossOtherThanTemporaryImpairmentsAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Cash outflow for purchase of trading, available-for-sale securities and held-to-maturity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

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

The cash inflow associated with the sale 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.

Name:	us-gaap_ProceedsFromSaleOfEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

Name:	dei_LegalEntityAxis=ghc_BerkshireHathawayIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=ghc_CorinthianCollegesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=ghc_StrayerEducationIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ghc_TransactionAxis=ghc_BerkshireExchangeTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ghc_BowaterMerseyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ghc_ClassifiedVenturesLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ghc_ClassifiedVenturessaleofapartments.comMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ghc_ResidentialHomeHealthIllinoisMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: