Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Total revenue	$ 2,286	$ 465
Type of Revenue [Extensible List]	us-gaap:CollaborativeArrangementMember	us-gaap:CollaborativeArrangementMember
Operating costs and expenses:
Cost of goods sold	$ 170
Research and development	63,610	$ 86,398
Selling, general and administrative	70,130	83,919
Total operating costs and expenses	133,910	170,317
Loss from operations	(131,624)	(169,852)
Interest income, net	4,729	6,442
Other income, net	155	4
Net loss	$ (126,740)	$ (163,406)
Net loss per share—basic and diluted	$ (2.44)	$ (3.37)
Weighted average number of common shares outstanding—basic and diluted	51,908,760	48,491,834
Comprehensive loss:
Net loss	$ (126,740)	$ (163,406)
Other comprehensive items:
Unrealized gain (loss) on marketable securities	(2,087)	409
Total other comprehensive gain (loss)	(2,087)	409
Total comprehensive loss	(128,827)	(162,997)
Product Revenue [Member]
Total revenue	$ 2,286
Collaboration Revenue [Member]
Total revenue		$ 465