Earnings (Loss) Per Share (Details 1) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Schedule of Earnings Per Share, Basic and Diluted, Including Two Class Method [Line Items]
Net income (loss) attributable to Graham Holdings Company common stockholders	$ 72,503	$ (23,031)	$ 175,843	$ 152,029
Less: Dividends paid-common stock outstanding and unvested restricted shares	(7,444)	(7,458)	(30,370)	(30,992)
Undistributed earnings (loss)	$ 65,059	$ (30,489)	$ 145,473	$ 121,037
Percent allocated to common stockholders (1)	99.31%	100.00%	99.31%	99.35%
Undistributed Earnings (Loss) Allocated To Common Stockholders	$ 64,612	$ (30,489)	$ 144,473	$ 120,253
Add: Dividends paid-common stock outstanding	7,392	7,409	30,164	30,797
Numerator for basic earnings (loss) per share	72,004	(23,080)	174,637	151,050
Add: Additional undistributed earnings due to dilutive stock options	3	0	6	2
Numerator for diluted earnings (loss) per share	$ 72,007	$ (23,080)	$ 174,643	$ 151,052
Weighted average shares outstanding (shares)	4,352	4,602	4,395	4,686
Denominator for diluted earnings (loss) per share (shares)	4,384	4,602	4,423	4,700
Graham Holdings Company Common Stockholders:
Basic income (loss) per common share (in USD per share)	$ 16.54	$ (5.02)	$ 39.74	$ 32.23
Diluted income (loss) per common share (in USD per share)	$ 16.42	$ (5.02)	$ 39.49	$ 32.14
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)	32	0	28	14