Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (39,209)	$ 20,267	$ (68,920)	$ (1,420)
Unrealized gain (loss) on available-for-sale securities	(67)	271	(195)	170
Comprehensive income (loss)	$ (39,276)	$ 20,538	$ (69,115)	$ (1,250)