Accumulated Other Comprehensive Income Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) Roll Forward [Line Items]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ 0		$ 0		$ 0	$ 0
Unrealized gain on available-for-sale investments, net of tax (benefit)	0		0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	12,331		15,913
Other Comprehensive Income Loss Arising During Period Total Net of Tax	12,331		15,913
Foreign currency translation adjustment	12,331	$ (12,653)	15,913	$ (9,238)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(51,067)		(54,649)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(38,736)		(38,736)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	2,251	0	(110)
Other comprehensive income (loss), net of tax	12,331	$ (10,402)	15,913	$ (9,348)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (38,736)		$ (38,736)		$ (51,067)	$ (54,649)