CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Foreign currency translation, tax	$ 24,150	$ 24,818	$ (8,086)
Prior service cost recognized in net periodic cost, tax	$ 0	9	9
Transition obligation recognized in net periodic cost, tax		0	(2)
Unamortized (loss) gain arising during the period, tax	$ 1,469	26,624	(14,638)
Net loss recognized in net periodic cost, tax	(2,242)	(1,544)	(2,446)
Foreign currency translation, tax	(316)	(265)	(66)
Unrealized gain (loss) on derivatives arising during the period, tax	379	(111)	(265)
Reclassification adjustment on derivatives included in net income, tax	$ (196)	$ 111	$ 46