Earnings Per Share (Details 1) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items]
Net Income attributable to Graham Holdings Company common stockholders	$ 24,784	$ 33,126	$ 87,866	$ 131,672
Less: Dividends paid-common stock outstanding and unvested restricted shares	(7,047)	(6,796)	(28,329)	(27,329)
Undistributed earnings	$ 17,737	$ 26,330	$ 59,537	$ 104,343
Percent allocated to common stockholders	99.07%	98.70%	99.07%	98.70%
Undistributed Earnings Allocated To Common Stockholders	$ 17,572	$ 25,987	$ 58,981	$ 102,987
Add: Dividends paid-common stock outstanding	6,981	6,708	28,066	26,976
Numerator for basic earnings per share	24,553	32,695	87,047	129,963
Add: Additional undistributed earnings due to dilutive stock options	1	2	4	7
Numerator for diluted earnings per share	$ 24,554	$ 32,697	$ 87,051	$ 129,970
Weighted average shares outstanding (shares)	5,518	5,544	5,530	5,570
Denominator for diluted earnings per share (shares)	5,554	5,574	5,567	5,600
Graham Holdings Company Common Stockholders:
Basic income per common share in dollars per share	$ 4.45	$ 5.90	$ 15.74	$ 23.33
Diluted income per common share in dollars per share	$ 4.42	$ 5.87	$ 15.64	$ 23.21
Stock Option Plan [Member]
Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items]
Add: Effect of dilutive stock options (shares)	36	30	37	30