Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 39,109	$ 35,333	$ 127,357	$ 118,663
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on hedging activities, net of tax (1)	[1]	1,075	335	1,886	(124)
Foreign currency translation adjustments, net of tax (2)	[2]	1,737	20,004	(36,670)	80,174
Defined benefit pension and other postretirement benefits, net of tax (3)	[3]	2,193	1,640	8,382	3,576
Total other comprehensive income (loss), net of tax		5,005	21,979	(26,402)	83,626
Total comprehensive income		44,114	57,312	100,955	202,289
Unrealized (loss) income on hedging activities, tax		315	125	593	(87)
Foreign currency translation adjustment, tax		43	146	(119)	526
Defined benefit pension and other postretirement benefits, tax		$ 750	$ 946	$ 2,813	$ 2,749

[1] Net of tax of $315 and $125 for the three months ended September 30, 2018 and 2017, respectively, and $593 and $(87) for the nine months ended September 30, 2018 and 2017, respectively.

[2] Net of tax of $43 and $146 for the three months ended September 30, 2018 and 2017, respectively, and $(119) and $526 for the nine months ended September 30, 2018 and 2017, respectively.

[3] Net of tax of $750 and $946 for the three months ended September 30, 2018 and 2017, respectively, and $2,813 and $2,749 for the nine months ended September 30, 2018 and 2017, respectively.