Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2019	39,203,304
Balance at Dec. 31, 2019	$ 4,000	$ 1,295,033,000	$ 62,000	$ (1,277,636,000)	$ 17,463,000
Stock-based compensation	$ 0	36,575,000	0	0	36,575,000
Shares issued or restricted stock units vested under employee stock plans (in shares)	883,083
Shares issued or restricted stock units vested under employee stock plans	$ 0	68,000	0	0	68,000
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	0	3,000
Unrealized gain (loss) on available-for-sale securities, net of tax of $0, $0 and $0	0	0	(65,000)	0	(65,000)
Net Income (Loss) Attributable to Parent, Total	0	0	0	(59,995,000)	(59,995,000)
Net income (loss)	$ 0	0	0	(59,995,000)	(59,995,000)
Balance (in shares) at Dec. 31, 2020	40,086,387
Balance at Dec. 31, 2020	$ 4,000	1,331,676,000	0	(1,337,631,000)	(5,951,000)
Stock-based compensation	$ 0	32,633,000	0	0	32,633,000
Shares issued or restricted stock units vested under employee stock plans (in shares)	1,089,120
Shares issued or restricted stock units vested under employee stock plans	$ 0	0	0	0	0
Reclassifications of gain on available-for-sale securities, included in “Other income (expenses)", net of tax of $0, $0 and $0					0
Unrealized gain (loss) on available-for-sale securities, net of tax of $0, $0 and $0	0	0	(2,000)	0	(2,000)
Net Income (Loss) Attributable to Parent, Total	0	0	0	(29,126,000)	(29,126,000)
Net income (loss)	$ 0	0	0	(29,126,000)	$ (29,126,000)
Balance (in shares) at Dec. 31, 2021	41,175,507				41,175,507
Balance at Dec. 31, 2021	$ 4,000	1,364,309,000	(2,000)	(1,366,757,000)	$ (2,446,000)
Stock-based compensation	$ 0	11,826,000	0	0	11,826,000
Shares issued or restricted stock units vested under employee stock plans (in shares)	1,017,744
Shares issued or restricted stock units vested under employee stock plans	$ 0	0	0	0	0
Reclassifications of gain on available-for-sale securities, included in “Other income (expenses)", net of tax of $0, $0 and $0					0
Unrealized gain (loss) on available-for-sale securities, net of tax of $0, $0 and $0	0	0	2,000	0	2,000
Net Income (Loss) Attributable to Parent, Total	0	0	0	2,000	2,000
Net income (loss)	$ 0	0	0	2,000	2,000
Shares issued under private investments in public equity, net of issuance costs of approximately $0.2M (in shares)	4,152,409
Shares issued under private investments in public equity, net of issuance costs of approximately $0.2M	$ 1,000	12,223,000	0	0	$ 12,224,000
Balance (in shares) at Dec. 31, 2022	46,345,660				41,175,507
Balance at Dec. 31, 2022	$ 5,000	$ 1,388,358,000	$ 0	$ (1,366,755,000)	$ 21,608,000