Shareholders' Equity Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Before-tax amount [Abstract]
Foreign currency translation adjustment	$ 5,352	$ (34,271)	$ 3,098	$ (17,978)
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	651	3,068	822	4,504
Net hedging (gain) loss reclassified into net income	(2,610)	(2,354)	(2,874)	(2,373)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax	378	0	720	0
Net defined benefit plan loss reclassified to net income	(189)	409	(10)	829
Total other comprehensive income (loss), before tax	3,582	(33,148)	1,756	(15,018)
Tax (provision) benefit [Abstract]
Foreign currency translation adjustment	(165)	111	(297)	118
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	136	(173)	176	(426)
Net hedging (gain) loss reclassified into net income	189	(55)	377	(50)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax	(42)	0	(57)	0
Net defined benefit plan loss reclassified to net income	36	(8)	1	(14)
Total other comprehensive income (loss) tax benefit	(154)	125	(200)	372
Net-of-tax amount [Abstract]
Foreign currency translation adjustment	5,187	(34,160)	2,801	(17,860)
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	787	2,895	998	4,078
Net hedging (gain) loss reclassified into net income	(2,421)	(2,409)	(2,497)	(2,423)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	336	0	663	0
Net defined benefit plan loss reclassified to net income	(153)	401	(9)	815
Total other comprehensive income (loss), net of tax	$ 3,736	$ (33,273)	$ 1,956	$ (15,390)