Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Summary of Restricted Stock Award and Unit Activity (Details)

v3.20.4
Stock-Based Compensation - Summary of Restricted Stock Award and Unit Activity (Details) - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Restricted stock      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Beginning of period (in shares) 4,098,318 1,535,811 976,027
Granted (in shares) 3,069,521 4,011,073 1,579,911
Vested (in shares) (1,294,285) (676,108) (626,671)
Forfeited (in shares) (4,171,041) (772,458) (393,456)
End of period (in shares) 1,702,513 4,098,318 1,535,811
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Weighted average grant date fair value, beginning of period (in dollars per share) $ 4.73 $ 11.57 $ 18.71
Granted, weighted average grant date fair value (in dollars per share) 0.85 3.74 9.90
Vested, weighted average grant date fair value (in dollars per share) 5.73 12.89 18.05
Forfeited, weighted average grant date fair value (in dollars per share) 1.68 6.05 12.23
Weighted average grant date fair value,, end of period (in dollars per share) $ 4.74 $ 4.73 $ 11.57
Performance Shares      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Beginning of period (in shares) 1,783,660 0 0
Granted (in shares) 0 2,009,144 0
Vested (in shares) 0 0 0
Forfeited (in shares) (943,065) (225,484) 0
End of period (in shares) 840,595 1,783,660 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Weighted average grant date fair value, beginning of period (in dollars per share) $ 2.96 $ 0 $ 0
Granted, weighted average grant date fair value (in dollars per share) 0 2.85 0
Vested, weighted average grant date fair value (in dollars per share) 0 0 0
Forfeited, weighted average grant date fair value (in dollars per share) 1.98 1.98 0
Weighted average grant date fair value,, end of period (in dollars per share) $ 4.07 $ 2.96 $ 0