Accumulated Other Comprehensive Loss (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 (Loss) Income [Line Items]
Beginning Balance	$ 181,804	$ 71,820	$ 265,849	$ 16,450
Other comprehensive (loss) income before reclassifications			(209)	48
Other comprehensive loss, net of tax:	195	104	(14)	48
Ending Balance	114,560	399,686	114,560	399,686
Reclassification from AOCI	200		195
Currency Translation Adjustments
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning Balance			(347)	(323)
Other comprehensive (loss) income before reclassifications			(9)	(16)
Other comprehensive loss, net of tax:			186	(16)
Ending Balance	(161)	(339)	(161)	(339)
Reclassification from AOCI			195
Net Unrealized Gains (Losses) on Available- for-Sale Securities
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning Balance			(4)	(78)
Other comprehensive (loss) income before reclassifications			(200)	64
Other comprehensive loss, net of tax:			(200)	64
Ending Balance	(204)	(14)	(204)	(14)
Reclassification from AOCI			0
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning Balance	(560)	(457)	(351)	(401)
Other comprehensive loss, net of tax:	195	104	(14)	48
Ending Balance	$ (365)	$ (353)	$ (365)	$ (353)