Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 17,144	$ (36,288)	$ 43,666	$ (50,570)
Other comprehensive income (loss):
Unrealized gains (losses) on available-for-sale securities, net of tax of $0	(42)	(315)	35	(201)
Comprehensive income (loss)	$ 17,102	$ (36,603)	$ 43,701	$ (50,771)