Revision of Prior Period Financial Statements - Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jan. 01, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accrued expenses	$ 144,567	$ 183,382
Accumulated deficit	$ (1,051,153)	(1,015,201)
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accrued expenses		177,079
Accumulated deficit		(1,008,898)
Revision of Prior Period, Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accrued expenses		6,303
Accumulated deficit		$ (6,303)	$ (5,100)