CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (48,134)	$ (50,071)	$ (44,426)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of income tax (expense) of ($5), ($9), and ($2) for the years ended December 31, 2019, 2018 and 2017, respectively	13	26	(159)
Unrealized gain (loss) on available-for-sale securities, net of income tax (expense) benefit of ($60), $0, and $2 for the years ended December 31, 2019, 2018 and 2017, respectively	176	0	(60)
Other comprehensive income (loss), net of tax	189	26	(219)
Comprehensive loss	$ (47,945)	$ (50,045)	$ (44,645)