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v3.23.1

Other Non-Operating Income (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Education [Member] | Higher Education [Member] | Kaplan University Transaction [Member] |  |
Schedule of Non-Operating Income (Expense) [Line Items] |  |
Gain related to contingent consideration | $ 1.0 | $ 0.9

X
- Definition Contingent consideration gain related to the sale of a business. + References No definition available. + Details
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Namespace Prefix: | ghc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition [Line Items] for Schedule of Non-Operating Income (Expense) [Table] + References No definition available. + Details
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Namespace Prefix: | ghc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ghc_EducationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsegmentsAxis=ghc_HigherEducationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ghc_TransactionAxis=ghc_KaplanUniversityTransactionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |