Capital Stock, Stock Awards, and Stock Options (Earnings Per Share) (Details 5) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items]
Income from continuing operations attributable to Graham Holdings Company common stockholders	$ 332,102	$ 83,331	$ 374,948	$ 130,366	$ 50,138	$ 54,132	$ 46,447	$ 21,278	$ 920,747	$ 171,995	$ 50,323
Less: Dividends paid–common stock outstanding and unvested restricted shares									(67,267)	0	(146,432)
Undistributed earnings (losses)									853,480	171,995	(96,109)
Percent allocated to common stockholders (1)									97.98%	98.45%	100.00%
Undistributed earnings allocated to common stockholders									836,246	169,329	(96,109)
Add: Dividends paid–common stock outstanding									66,012	0	143,175
Numerator for basic earnings per share									902,258	169,329	47,066
Add: Additional undistributed earnings due to dilutive stock options									79	5	0
Numerator for diluted earnings per share									$ 902,337	$ 169,334	$ 47,066
Denominator for basic earnings per share (shares)	5,678	5,671	7,284	7,275	7,266	7,231	7,229	7,227	6,470	7,238	7,360
Denominator for diluted earnings per share (shares)									6,497	7,250	7,360
Income Per Share From Continuing Operations To Common Stockholders [Abstract]
Basic earnings per share from continuing operations (in dollars per share)	$ 57.31	$ 14.38	$ 50.39	$ 17.62	$ 6.79	$ 7.29	$ 6.26	$ 2.87	$ 139.44	$ 23.39	$ 6.40
Diluted earnings per share from continuing operations (in dollars per share)	$ 57.01	$ 14.32	$ 50.22	$ 17.56	$ 6.77	$ 7.28	$ 6.26	$ 2.87	$ 138.88	$ 23.36	$ 6.40
Employee Stock Option [Member]
Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items]
Add: Effect of dilutive stock options (shares)									27	12	0