Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net Loss Attributable to Common Stockholders	$ (59,937,000)	$ (8,857,000)	$ (63,509,000)
Other comprehensive gain (loss), net of tax:
Unrealized gain (loss) on short-term investments, net of tax	17,000	(17,000)	0
Foreign currency translation adjustment	29,000
Other comprehensive gain (loss), net of tax	46,000	(17,000)
Comprehensive Net Loss	$ (59,891,000)	$ (8,874,000)	$ (63,509,000)