Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (152,845)	$ (193,798)	$ (136,057)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			0
Foreign currency translation adjustment	$ 15,791	(763)	63,475	(3,767)
Unrealized gain on available for sale securities	6,596	0	9,534	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax			9,534
Other comprehensive income before reclassifications			73,315	(5,692)
Amounts reclassified from accumulated other comprehensive loss			(341)	478
Net current-period other comprehensive income (loss), before income taxes	22,213	133	72,974	(5,214)
Income tax expense	(2,363)	(1,363)	(3,495)	(11,574)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax			(3,508)
Other comprehensive income, net of income taxes	19,850	(1,230)	69,479	(16,788)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			6,026
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	6,026		6,026
Ending balance	(124,319)		(124,319)
Cash Flow Hedging [Member] | Interest Expense [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(224)	146	(341)	478
Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	50	750	306	(1,925)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(152,307)	(194,189)	(136,434)
Amounts reclassified from accumulated other comprehensive loss			0	0
Net current-period other comprehensive income (loss), before income taxes			63,475	(3,767)
Income tax expense			0	(12,106)
Other comprehensive income, net of income taxes			63,475	(15,873)
Ending balance	(130,714)		(130,714)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (538)	391	377
Net current-period other comprehensive income (loss), before income taxes			(35)	(1,447)
Income tax expense			13	532
Other comprehensive income, net of income taxes			(22)	$ (915)
Ending balance	$ 369		$ 369