Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 81,702	$ 42,965
Foreign currency translation adjustments:
Translation adjustments arising during the period	10,033	11,564
Pension and other postretirement plans:
Amortization of net prior service (credit) cost included in net income	(1,347)	76
Amortization of net actuarial gain included in net income	(548)	(1,367)
Total pension and other postretirement plans, before tax	(1,895)	(1,291)
Cash flow hedges (loss) gain	(467)	236
Other Comprehensive Income, Before Tax	7,671	10,509
Income tax benefit related to items of other comprehensive income	619	303
Other Comprehensive Income, Net of Tax	8,290	10,812
Comprehensive Income	89,992	53,777
Comprehensive loss (income) attributable to noncontrolling interests	46	(74)
Total Comprehensive Income Attributable to Graham Holdings Company	$ 90,038	$ 53,703