Percent of noncontrolling interest purchased during the period.

No definition available.

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Namespace Prefix:	ghc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)(1)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479

+ Details

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

- Definition

Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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Period Type:	duration

Acquisitions and Dispositions (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended				3 Months Ended	12 Months Ended							1 Months Ended	0 Months Ended
	Dec. 31, 2013 business	Dec. 31, 2012 business	Dec. 31, 2011 business	Nov. 30, 2012 Celtic Healthcare, Inc. [Member]	Jun. 30, 2013 Education [Member]	Dec. 31, 2013 Education [Member] business	Dec. 31, 2012 Education [Member] business	Dec. 31, 2011 Kaplan International [Member] business	Dec. 31, 2011 Kaplan Ventures [Member] business	Dec. 31, 2011 Higher Education [Member] business	Dec. 31, 2013 Other Businesses [Member] business	Dec. 31, 2012 Other Businesses [Member] business	Nov. 30, 2012 Other Businesses [Member] Celtic Healthcare, Inc. [Member] business	Aug. 01, 2013 Other Businesses [Member] Forney Corporation [Member] business
Business Acquisition [Line Items]
Number of businesses acquired	6	5	5			1	3	3	1	1	4	1	1	1
Cost of acquisition	$ 23.8	$ 55.6	$ 136.5
Noncontrolling Interest Purchased					15.00%
Assumed debt			5.5
Fair value of the noncontrolling interest				$ 5.9