Summary of Significant Accounting Policies - Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (986,973)	$ (929,318)
Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount interest accretion would have been without ASU 2020-06 adoption	2,300
Outstanding principle	287,500
Net carrying amount	$ 279,471
Previously reported | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Outstanding principle		287,500
Unamortized debt discount and issuance cost		(85,007)
Net carrying amount		202,493
Additional paid-in-capital		(1,411,286)
Accumulated deficit		(929,318)
ASU 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment			$ 400
Accounting Standards Update 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income from continuing operations per common share	$ 0.03
Accounting Standards Update 2020-06 | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Outstanding principle		287,500
Unamortized debt discount and issuance cost		(8,333)
Net carrying amount		279,167
Additional paid-in-capital		(1,328,414)
Accumulated deficit		(923,120)
Accounting Standards Update 2020-06 | Adoption Adjustment | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt discount and issuance cost		76,674
Net carrying amount		76,674
Additional paid-in-capital		82,872
Accumulated deficit		$ 6,198