Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Net product sales	$ 145,968	$ 77,474	$ 30,767
Operating expenses:
Cost of product sales	61,619	27,512	4,588
Research and development	167,382	140,032	138,582
General and administrative	37,897	29,263	25,554
Sales and marketing	89,764	64,604	56,601
Total operating expenses	356,662	261,411	225,325
Loss from operations	(210,694)	(183,937)	(194,558)
Other income (expense), net:
Interest income	7,259	5,965	1,049
Interest expense	(1,472)	(2,672)	(3,937)
Other income (expense)	158	1,804	(38)
Total other income (expense), net	5,945	5,097	(2,926)
Net loss	(204,749)	(178,840)	(197,484)
Other comprehensive loss:
Unrealized gains (losses) on short-term investments	172	(77)	7
Comprehensive loss	$ (204,577)	$ (178,917)	$ (197,477)
Basic and diluted net loss per share	$ (2.50)	$ (2.44)	$ (3.65)
Shares used in computing basic and diluted net loss per share	81,779	73,193	54,040