Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Restricted stock units and Equity Grants (Details)

v3.21.1
Stock-based Compensation - Restricted stock units and Equity Grants (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Nov. 25, 2020
Jan. 31, 2021
Dec. 31, 2020
Aug. 31, 2020
Dec. 31, 2020
Dec. 21, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized     18,162,573   18,162,573 26,898,554 15,281,513 7,064,779
Vesting period         4 years      
RSUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized 1,003,828     8,027,473        
Granted       4,285,026        
Number of shares per unit       1        
Share-based compensation expense     $ 3.5          
Number of shares for which authorization has been withdrawn 2,503,011              
Shares approved but not yet granted 1,239,435              
Shares cancelled 240,441              
Shares whose vesting was accelerated 998,994              
Grant date fair value     11.7   $ 11.7      
RSUs | Subsequent Event [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Expense for accelerated vesting   $ 18.0            
PSUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized 1,003,828              
Mr. Aquila                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share-based compensation expense     $ 1.0          
Mr. Aquila | RSUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized 1,003,828              
Total fair value of shares granted $ 19.4              
Number of shares per unit 1              
Vesting period 3 years              
Mr. Aquila | PSUs                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized 1,003,828              
Total fair value of shares granted $ 15.6              
Number of shares per unit 1