Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 35,333	$ 36,828	$ 118,663	$ 98,888
Other comprehensive income, net of tax
Unrealized gains (losses) on hedging activities, net of tax (1)	[1]	335	(150)	(124)	(580)
Foreign currency translation adjustments, net of tax (2)	[2]	20,004	990	80,174	2,100
Defined benefit pension and other postretirement benefits, net of tax (3)	[3]	1,640	2,042	3,576	5,740
Total other comprehensive income, net of tax		21,979	2,882	83,626	7,260
Total comprehensive income		57,312	39,710	202,289	106,148
Unrealized (loss) income on hedging activities, tax		125	1	(87)	(141)
Foreign currency translation adjustment, tax		146	31	526	105
Defined benefit pension and other postretirement benefits, tax		$ 946	$ 977	$ 2,749	$ 2,930

[1] Net of tax of $125 and $1 for the three months ended September 30, 2017 and 2016, respectively, and $(87) and $(141) for the nine months ended September 30, 2017 and 2016, respectively.

[2] Net of tax of $146 and $31 for the three months ended September 30, 2017 and 2016, respectively, and $526 and $105 for the nine months ended September 30, 2017 and 2016, respectively.

[3] Net of tax of $946 and $977 for the three months ended September 30, 2017 and 2016, respectively, and $2,749 and $2,930 for the nine months ended September 30, 2017 and 2016, respectively.