CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax	$ (2,314)	$ 7,151	$ (5,924)
Net gains (losses) on cash flow hedging instruments, deferred income taxes	(975)	(338)	(1,410)
Pension liability adjustments, deferred income taxes	(14,240)	13,454	(11,095)
Unrealized gain (loss) on marketable securities, deferred income taxes	$ 10	$ (3)	$ (18)