Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 94,476	$ 78,172	$ 167,757	$ 135,772
Other comprehensive income (loss), net of tax:
Changes in net prior service credit and actuarial losses	1,876	1,809	3,754	2,748
Change in fair value of derivatives	828	104	1,469	(2,351)
Foreign currency translation	25,669	(1,576)	(7,703)	(38,015)
Other comprehensive income (loss)	28,373	337	(2,480)	(37,618)
Comprehensive income	$ 122,849	$ 78,509	$ 165,277	$ 98,154