Immaterial Restatement Of Prior Period Financial Statements - Summary of Revisions to the Consolidated Statements of Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (40,200)	$ (26,557)	$ (28,783)	$ (39,846)	$ (53,117)	$ (69,209)	$ 14,863	$ (19,243)	$ (112,689)	$ (120,741)	$ (92,189)
Total comprehensive loss									$ (112,485)	(123,231)	(74,611)
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss										(120,011)	(91,248)
Total comprehensive loss										(122,501)	(73,670)
Adjustments for Error Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss				$ 26	$ 38	$ 37	$ 31	$ 71		(730)	(941)
Total comprehensive loss										$ (730)	$ (941)