Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 38,818	$ 38,303
Other comprehensive income, net of tax
Unrealized gain on hedging activities, net of tax (1)	[1]	396	83
Foreign currency translation adjustments, net of tax (2)	[2]	26,953	18,609
Defined benefit pension and other postretirement benefits, net of tax (3)	[3]	3,164	1,265
Total other comprehensive income, net of tax		30,513	19,957
Total comprehensive income		69,331	58,260
Unrealized (loss) income on hedging activities, tax		148	38
Foreign currency translation adjustment, tax		162	67
Defined benefit pension and other postretirement benefits, tax		$ 1,257	$ 901

[1] Net of tax of $148 and $38 for the three months ended March 31, 2018 and 2017, respectively.

[2] Net of tax of $162 and $67 for the three months ended March 31, 2018 and 2017, respectively.

[3] Net of tax of $1,257 and $901 for the three months ended March 31, 2018 and 2017, respectively.