CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, deferred income taxes	$ (16,992)	$ (3,747)	$ (27,680)	$ (855)
Net gain (loss) on cash flow hedging instruments, deferred income taxes	(813)	(799)	(398)	(1,337)
Pension liability adjustments, deferred income taxes	336	(466)	(920)	(1,405)
Unrealized gain (loss) on marketable securities, deferred income taxes	$ (9)	$ 4	$ (7)	$ 7