Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Total revenues	$ 104,754	$ 69,056	$ 68,458
Costs and operating expenses:
Cost of product revenue	22,209	13,742	15,632
Research and development	55,919	44,185	33,873
Selling, general and administrative	49,323	35,049	31,502
Total costs and operating expenses	127,451	92,976	81,007
Income (loss) from operations	(22,697)	(23,920)	(12,549)
Interest income	459	405	1,287
Other income (expense), net ($983, $0 and $0 from a related party)	1,148	(156)	(656)
Loss before income taxes	(21,090)	(23,671)	(11,918)
Provision for income taxes	189	339	17
Net loss	$ (21,279)	$ (24,010)	$ (11,935)
Net loss per share, basic (in dollars per share)	$ (0.33)	$ (0.40)	$ (0.21)
Net loss per share, diluted (in dollars per share)	$ (0.33)	$ (0.40)	$ (0.21)
Weighted average common stock shares used in computing net loss per share, basic (in shares)	64,568	59,360	56,525
Weighted average common stock shares used in computing net loss per share, diluted (in shares)	64,568	59,360	56,525
Product revenue
Revenues:
Total revenues	$ 70,657	$ 30,220	$ 29,465
Research and development revenue ($1,955, $900 and $0 from a related party)
Revenues:
Total revenues	$ 34,097	$ 38,836	$ 38,993