CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Product revenue, net	$ 93,688	$ 79,437
Operating expenses:
Cost of sales	1,250	1,268
Research and development	28,120	29,022
Selling, general and administrative	37,549	29,509
Total operating expenses	66,919	59,799
Income from operations	26,769	19,638
Interest and other income	80	275
Income before income taxes	26,849	19,913
Income tax (expense) benefit	(4,052)	3,552
Net income	22,797	23,465
Other comprehensive income:
Unrealized loss on available-for-sale investments, net of tax effect of $323 and $61, respectively	(1,019)	(192)
Foreign currency translation (loss) gain, net of tax	(105)	26
Total comprehensive income	$ 21,673	$ 23,299
Basic net income per share (in dollars per share)	$ 0.22	$ 0.20
Diluted net income per share (in dollars per share)	$ 0.20	$ 0.18
Weighted-average shares outstanding used in computing net income per share
Basic (in shares)	106,012	116,818
Diluted (in shares)	115,037	129,668