Income Taxes - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Apr. 02, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax [Line Items]        
US Federal Net Operating Loss Carryover, Subject to Expiration [Line Items]   $ 417,400    
Domestic Tax Authority        
Income Tax [Line Items]        
Operating loss carryforwards   496,300    
State        
Income Tax [Line Items]        
Operating loss carryforwards   93,200    
Conversion of common shares from Class C to Class A | Common Class A        
Income Tax [Line Items]        
Conversion of Convertible Securities, Income Tax Expense (Benefit) $ 2,200 $ 2,200 $ 17,500 $ 7,200