Nature of Business and Plan of Operations (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	12 Months Ended
	Jan. 31, 2021	Mar. 01, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net loss			$ (44,372)	$ (104,133)	$ (168,843)
Accumulated deficit			(1,331,840)	(1,287,468)
Total revenues			132,299	82,271	53,446
Cash and cash equivalents			$ 293,856	$ 176,225	$ 262,252	$ 267,107
Number of months Capital resources meets capital expenditures			12 months
Product
Total revenues			$ 0
Open Market Sale Agreement | Subsequent event
Consideration received from sale of common stock	$ 33,600	$ 33,600