Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Unusual or Infrequent Item, or Both [Line Items]
Accumulated deficit	$ 1,299.5	$ 1,331.2
Additional paid-in capital	$ (1,975.6)	$ (1,791.8)
Restatement Adjustment
Unusual or Infrequent Item, or Both [Line Items]
Accumulated deficit			$ 60.6
Warrant liabilities			55.7
Additional paid-in capital			$ (116.3)