Annual report pursuant to Section 13 and 15(d)

Equity - Unvested Restricted Common Stock (Details)

v3.22.0.1
Equity - Unvested Restricted Common Stock (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Restricted Incentive    
Shares    
Beginning Balance (in shares) 367,177 750,242
Granted (in shares) 80,886 194,077
Vested (in shares) (250,758) (576,880)
Forfeited (in shares) (3,757) (262)
Ending Balance (in shares) 193,548 367,177
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 27.77 $ 20.08
Granted (in usd per share) 59.41 32.93
Vested (in usd per share) 29.22 19.50
Forfeited (in usd per share) 51.43 28.59
Ending Balance (in usd per share) $ 38.66 $ 27.77
Value    
Beginning Balance $ 10.2 $ 15.1
Granted 4.8 6.4
Vested (7.3) (11.3)
Forfeited (0.2) 0.0
Ending Balance $ 7.5 $ 10.2
Restricted Stock Units    
Shares    
Beginning Balance (in shares) 235,600 435,578
Granted (in shares) 17,426 23,342
Vested (in shares) (342,360) (439,986)
Forfeited (in shares) (3,480) (266)
Ending Balance (in shares) 78,366 235,600
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 21.78 $ 20.12
Granted (in usd per share) 71.23 27.18
Vested (in usd per share) 20.24 19.04
Forfeited (in usd per share) 39.92 25.90
Ending Balance (in usd per share) $ 35.32 $ 21.78
Value    
Beginning Balance $ 5.1 $ 8.8
Granted 1.2 0.6
Vested (6.9) (8.4)
Forfeited (0.1) 0.0
Ending Balance $ 2.8 $ 5.1
Restricted Stock Units | Minimum    
Value    
Award vesting percentage 0.00%  
Restricted Stock Units | Maximum    
Value    
Award vesting percentage 200.00%  
Incremental performance shares granted    
Shares    
Granted (in shares) 171,180 216,932
Weighted Average Grant Date Fair Value    
Granted (in usd per share) $ 20.24 $ 18.99
Value    
Granted $ 3.5 $ 4.1
LTIP Time-Based Vesting Units    
Shares    
Beginning Balance (in shares) 285,682 201,310
Granted (in shares) 249,573 165,346
Vested (in shares) (151,209) (80,974)
Forfeited (in shares) 0 0
Ending Balance (in shares) 384,046 285,682
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 21.62 $ 25.84
Granted (in usd per share) 54.73 18.56
Vested (in usd per share) 21.58 25.87
Forfeited (in usd per share) 0 0
Ending Balance (in usd per share) $ 43.15 $ 21.62
Value    
Beginning Balance $ 6.2 $ 5.2
Granted 13.7 3.1
Vested (3.3) (2.1)
Forfeited 0.0 0.0
Ending Balance $ 16.6 $ 6.2
LTIP Market-Based Vesting Units    
Shares    
Beginning Balance (in shares) 312,704 180,500
Granted (in shares) 86,274 132,204
Vested (in shares) (103,000) 0
Forfeited (in shares) 0 0
Ending Balance (in shares) 347,478 312,704
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 20.59 $ 26.70
Granted (in usd per share) 65.28 12.25
Vested (in usd per share) 21.09 0
Forfeited (in usd per share) 0 0
Ending Balance (in usd per share) $ 31.61 $ 20.59
Value    
Beginning Balance $ 6.4 $ 4.8
Granted 5.6 1.6
Vested (2.1) 0.0
Forfeited 0.0 0.0
Ending Balance $ 11.0 $ 6.4
LTIP Market-Based Vesting Units | Minimum    
Value    
Award vesting percentage 0.00%  
LTIP Market-Based Vesting Units | Maximum    
Value    
Award vesting percentage 200.00%  
Incremental performance shares granted    
Shares    
Granted (in shares) 51,500  
Weighted Average Grant Date Fair Value    
Granted (in usd per share) $ 21.09  
Value    
Granted $ 1.1  
Award vesting percentage 200.00%