Condensed Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net (Loss) Income	$ (33,891)	$ 81,702
Foreign currency translation adjustments:
Translation adjustments arising during the period	(37,376)	10,033
Pension and other postretirement plans:
Amortization of net prior service cost (credit) included in net income	671	(1,347)
Amortization of net actuarial loss (gain) included in net income	220	(548)
Total pension and other postretirement plans, before tax	891	(1,895)
Cash flow hedges loss	(1,578)	(467)
Other Comprehensive (Loss) Income, Before Tax	(38,063)	7,671
Income tax benefit related to items of other comprehensive (loss) income	120	619
Other Comprehensive (Loss) Income, Net of Tax	(37,943)	8,290
Comprehensive (Loss) Income	(71,834)	89,992
Comprehensive loss attributable to noncontrolling interests	646	46
Total Comprehensive (Loss) Income Attributable to Graham Holdings Company	$ (71,188)	$ 90,038