Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ (193,798)	$ (136,057)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			0
Foreign currency translation adjustment	$ 37,820	$ (18,389)	47,684	(3,004)
Unrealized (loss) gain on available for sale securities	(1,083)	0	2,938	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax			2,938
Other comprehensive income before reclassifications			50,878	(5,679)
Amounts reclassified from accumulated other comprehensive loss			(117)	332
Net current-period other comprehensive income, before income taxes	36,557	(19,154)	50,761	(5,347)
Income tax benefit (expense)	465	(8,312)	(1,132)	(10,211)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax			(1,081)
Other comprehensive income, net of income taxes	37,022	(27,466)	49,629	(15,558)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			1,857
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	1,857		1,857
Ending balance	(144,169)	(151,615)	(144,169)	(151,615)
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	(115)	169	(117)	332
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	(65)	(934)	256	(2,675)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(194,189)	(136,434)
Amounts reclassified from accumulated other comprehensive loss			0	0
Net current-period other comprehensive income, before income taxes			47,684	(3,004)
Income tax benefit (expense)			0	(11,069)
Other comprehensive income, net of income taxes			47,684	(14,073)
Ending balance	(146,505)	(150,507)	(146,505)	(150,507)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			391	377
Net current-period other comprehensive income, before income taxes			139	(2,343)
Income tax benefit (expense)			(51)	858
Other comprehensive income, net of income taxes			88	(1,485)
Ending balance	$ 479	$ (1,108)	$ 479	$ (1,108)