Earnings Per Share (Details 1) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Numerator:
Net income attributable to Graham Holdings Company common stockholders	$ 29,106	$ 23,894
Less: Dividends paid-common stock outstanding and unvested restricted shares	(16,398)	(15,662)
Undistributed earnings	$ 12,708	$ 8,232
Percent allocated to common stockholders	99.44%	99.38%
Undistributed earnings allocated to common stockholders	$ 12,636	$ 8,182
Add: Dividends paid-common stock outstanding	16,306	15,563
Numerator for basic earnings per share	28,942	23,745
Add: Additional undistributed earnings due to dilutive stock options	1	0
Numerator for diluted earnings per share	$ 28,943	$ 23,745
Denominator:
Weighted average shares outstanding (shares)	4,331	4,320
Denominator for diluted earnings per share (shares)	4,375	4,358
Graham Holdings Company Common Stockholders:
Basic earnings per common share (in USD per share)	$ 6.68	$ 5.50
Diluted earnings per common share (in USD per share)	$ 6.62	$ 5.45
Stock Options [Member]
Denominator:
Add: Effect of dilutive stock options (shares)	44	38