Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Common Stock
Balance, beginning	$ 326,204	$ 419,476
Balance (in shares)	47,200,695
Shares issued under stock option and employee stock purchase plans	$ 694	304
Stock-based compensation	4,340	3,153
Unrealized loss on marketable securities	863	(1,782)
Net loss	(29,361)	(23,050)
Balance, ending	$ 302,740	398,101
Balance (in shares)	47,244,681
Aggregate gross offering price available	$ 50,000
Common Stock [Member]
Common Stock
Balance, beginning	$ 47	$ 47
Balance (in shares)	47,200,695	46,730,198
Shares issued under stock option and employee stock purchase plans	$ 0
Shares issued under stock option and employee stock purchase plans (in shares)	43,986	24,150
Stock-based compensation	$ 0
Unrealized loss on marketable securities	0
Net loss	0
Balance, ending	$ 47	$ 47
Balance (in shares)	47,244,681	46,754,348
Additional Paid-in Capital [Member]
Common Stock
Balance, beginning	$ 1,580,829	$ 1,561,142
Shares issued under stock option and employee stock purchase plans	694	304
Stock-based compensation	4,340	3,153
Unrealized loss on marketable securities	0
Net loss	0
Balance, ending	1,585,863	1,564,599
AOCI Attributable to Parent [Member]
Common Stock
Balance, beginning	1,260	1,894
Shares issued under stock option and employee stock purchase plans	0
Stock-based compensation	0
Unrealized loss on marketable securities	863	(1,782)
Net loss	0
Balance, ending	2,123	112
Retained Earnings [Member]
Common Stock
Balance, beginning	(1,255,932)	(1,143,607)
Shares issued under stock option and employee stock purchase plans	0
Stock-based compensation	0
Unrealized loss on marketable securities	0
Net loss	(29,361)	(23,050)
Balance, ending	$ (1,285,293)	$ (1,166,657)