Common Stock Incentive Plan - Summary (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2020	Oct. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Common Stock Incentive Plan
Severance charge	$ 3,500	$ 28,300
Incremental severance charge		18,700
Compensation accrual prior to separation		9,600
Share-based compensation costs related to accelerated equity awards					$ 11,800
Cash
Common Stock Incentive Plan
Severance charge	1,600	9,800
Share-based compensation
Common Stock Incentive Plan
Severance charge	1,800	17,900
Professional fees
Common Stock Incentive Plan
Severance charge	$ 58	$ 574
General and administrative expense
Common Stock Incentive Plan
Share-based compensation costs recognized			$ 16,500	$ 13,700	$ 27,300
2012 Plan
Common Stock Incentive Plan
Plan term from the date of adoption			10 years
2012 Plan | Maximum
Common Stock Incentive Plan
Authorized shares			3,985,734