Shareholders' Equity Schedule of Other Comprehensive Income (Loss) Tax Effect (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Before-tax amount [Abstract]
Foreign currency translation adjustment											$ (74,219)	$ (89,329)	$ 8,953
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax											(962)	0	0
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges											123	(915)	(3)
Net hedging (gain) loss reclassified into net income (loss)											1,639	1,704	697
Pension plan benefits liability adjustment											8,971	(25,270)	7,344
Total other comprehensive income (loss), before tax											(62,524)	(113,810)	16,991
Tax (provision) benefit [Abstract]
Foreign currency translation adjustment											328	32	(1,014)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax											0	0	0
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges											(47)	349	5
Net hedging (gain) loss reclassified into net income (loss)											(629)	(650)	(266)
Pension plan benefits liability adjustment											(2,675)	323	(2,227)
Total other comprehensive income (loss) tax (provision) benefit											(3,023)	54	(3,502)
Net-of-tax amount
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent											(73,891)	(89,297)	7,939
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax											962	0	0
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges											76	(566)	2
Net hedging (gain) loss reclassified into net income (loss)											1,010	1,054	431
Pension plan benefits liability adjustment	$ 866	$ 493	$ 504	$ 98	$ 118	$ 97	$ 997	$ 215	$ 1,863	$ 313	6,296	(24,947)	5,117
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent											$ (65,547)	$ (113,756)	$ 13,489