Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income (loss)	$ 2,000	$ (29,126,000)	$ (59,995,000)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net of tax of $0, $0 and $0	2,000	(2,000)	(65,000)
Reclassifications of gain on available-for-sale securities, included in “Other income (expenses)", net of tax of $0, $0 and $0	0	0	3,000
Comprehensive income (loss)	$ 4,000	$ (29,128,000)	$ (60,057,000)