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	$ (99,013)	$ (73,521)	$ (41,022)
Other comprehensive income, net of tax:
Unrealized gains on available-for-sale securities	50	0	0
Other comprehensive income	50	0	0
Comprehensive loss	$ (98,963)	$ (73,521)	$ (41,022)