CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 335,324	$ 461,466	$ 200,802
Foreign currency:
Foreign currency translation adjustments, net of tax of $6,442, $(6,270) and $(1,047), respectively	59,758	4,195	(83,889)
Foreign currency translation, net of tax	59,758	4,195	(83,889)
Pension and other postretirement benefits plans:
Prior service cost recognized in net periodic cost, net of tax of $(7), $(20) and $(23), respectively	26	62	71
Unamortized (loss) gain arising during the period, net of tax of $6,101, $3,817 and $(447), respectively	(19,966)	(12,767)	1,116
Plan amendments, curtailments, and settlements, net of tax of $(1,067), $0 and $(137), respectively	3,544	0	511
Net loss recognized in net periodic cost, net of tax of $(1,694), $(1,611) and $(1,588), respectively	5,559	5,319	5,231
Foreign currency translation, net of tax of $243, $15 and $(183), respectively	(610)	(44)	499
Pension and other postretirement benefits plans adjustment, net of tax	(11,447)	(7,430)	7,428
Derivatives qualifying as hedges:
Unrealized (loss) gain on derivatives arising during the period, net of tax $234, $(85) and $(268), respectively	(3,331)	1,062	2,574
Reclassification adjustment on derivatives included in net income, net of tax of $(240), $150 and $163, respectively	2,114	(1,134)	(2,107)
Derivatives qualifying as hedges, net of tax	(1,217)	(72)	467
Other comprehensive income (loss), net of tax	47,094	(3,307)	(75,994)
Comprehensive income	$ 382,418	$ 458,159	$ 124,808