Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 57,195	$ 46,635	$ 138,897	$ 89,600
Foreign currency translation adjustments:
Translation adjustments arising during the period	(11,104)	(31,167)	(1,071)	(19,603)
Pension and other postretirement plans:
Amortization of net prior service (credit) cost included in net income	(931)	70	(2,278)	146
Amortization of net actuarial gain included in net income	(475)	(3,294)	(1,023)	(4,661)
Total pension and other postretirement plans, before tax	(1,406)	(3,224)	(3,301)	(4,515)
Cash flow hedges gain (loss)	40	371	(427)	607
Other Comprehensive Loss, Before Tax	(12,470)	(34,020)	(4,799)	(23,511)
Income tax benefit related to items of other comprehensive loss	375	799	994	1,102
Other Comprehensive Loss, Net of Tax	(12,095)	(33,221)	(3,805)	(22,409)
Comprehensive Income	45,100	13,414	135,092	67,191
Comprehensive income attributable to noncontrolling interests	(114)	(69)	(68)	(143)
Total Comprehensive Income Attributable to Graham Holdings Company	$ 44,986	$ 13,345	$ 135,024	$ 67,048