Accumulated Other Comprehensive Income Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
AOCI, Debt Securities, Available-for-sale, Adjustment, after Tax	$ (858)		$ (1,418)
Unrealized gain (loss) on available-for-sale investments, net of tax (benefit)	(2)		558
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	(2)	$ 923	558	$ (1,577)
AOCI, Debt Securities, Available-for-sale, Adjustment, after Tax	(860)		(860)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(44,070)		(44,561)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(1,177)		(686)
Foreign currency translation adjustment	(1,177)	(14,648)	(686)	(8,338)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(45,247)		(45,247)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(44,928)		(45,979)
Other Comprehensive Income Loss Arising During Period Total Net of Tax	(1,179)		(128)
Other comprehensive loss, net of tax	(1,179)	$ (13,725)	(128)	$ (9,915)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ (46,107)		$ (46,107)