Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 57,600	$ 46,742
Other comprehensive income (loss), net of tax:
Changes in net prior service credit and actuarial losses	939	2,506
Change in fair value of derivatives	(2,455)	(887)
Foreign currency translation	(36,439)	(5,242)
Other comprehensive loss	(37,955)	(3,623)
Comprehensive income	$ 19,645	$ 43,119