CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 200,802	$ 152,530	$ 237,841
Foreign currency:
Foreign currency translation continuing operations adjustments, net of tax of 157, ($29,448) and $10,977, respectively	(83,889)	173,074	(69,162)
Foreign currency translation, net of tax	(83,889)	173,074	(69,162)
Pension and other postretirement benefits plans:
Prior service cost recognized in net periodic cost, net of tax of $(23), $(39), and $(20), respectively	71	66	36
Unamortized (loss) gain arising during the period, net of tax of $(447), $1,677, and $1,849, respectively	1,116	(5,419)	(3,255)
Plan amendments, curtailments, and settlements, net of tax of $(137), $74, and $0, respectively	511	(223)	0
Net loss recognized in net periodic cost, net of tax of $(1,588), $(2,457), and $(2,489), respectively	5,231	4,447	4,476
Foreign currency translation, net of tax of $(183), $413, and $(373), respectively	499	(1,083)	1,034
Pension and other postretirement benefits plans adjustment, net of tax	7,428	(2,212)	2,291
Derivatives qualifying as hedges:
Unrealized gain (loss) on derivatives arising during the period, net of tax $(268), $(631), and $1,359, respectively	2,574	2,775	(3,434)
Reclassification adjustment on derivatives included in net income, net of tax of $163, $83, and $(1,010), respectively	(2,107)	(11)	3,501
Derivatives qualifying as hedges, net of tax	467	2,764	67
Other comprehensive (loss) income, net of tax	(75,994)	173,626	(66,804)
Comprehensive income	124,808	326,156	171,037
Less: comprehensive income attributable to noncontrolling interest	0	0	421
Comprehensive income attributable to common shareholders	$ 124,808	$ 326,156	$ 170,616