Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 42,965	$ 125,070	$ 181,862	$ 214,670
Foreign currency translation adjustments:
Translation adjustments arising during the period	(16,684)	(2,844)	(17,755)	(22,447)
Pension and other postretirement plans:
Amortization of net prior service (credit) cost included in net income	(932)	69	(3,210)	215
Amortization of net actuarial gain included in net income	(511)	(3,295)	(1,534)	(7,956)
Total pension and other postretirement plans, before tax	(1,443)	(3,226)	(4,744)	(7,741)
Cash flow hedges (loss) gain	(477)	(6)	(904)	601
Other Comprehensive Loss, Before Tax	(18,604)	(6,076)	(23,403)	(29,587)
Income tax benefit related to items of other comprehensive loss	518	874	1,512	1,976
Other Comprehensive Loss, Net of Tax	(18,086)	(5,202)	(21,891)	(27,611)
Comprehensive Income	24,879	119,868	159,971	187,059
Comprehensive loss (income) attributable to noncontrolling interests	180	(6)	112	(149)
Total Comprehensive Income Attributable to Graham Holdings Company	$ 25,059	$ 119,862	$ 160,083	$ 186,910