Annual report pursuant to Section 13 and 15(d)

Equity - Unvested Restricted Common Stock (Details)

v3.24.0.1
Equity - Unvested Restricted Common Stock (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Restricted Incentive    
Shares    
Beginning Balance (in shares) 168,452 193,548
Granted (in shares) 77,938 71,911
Vested (in shares) (98,367) (93,646)
Forfeited (in shares) (12,356) (3,361)
Ending Balance (in shares) 135,667 168,452
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 33.59 $ 38.66
Granted (in usd per share) 30.03 37.32
Vested (in usd per share) 29.18 46.46
Forfeited (in usd per share) 42.74 46.83
Ending Balance (in usd per share) $ 33.90 $ 33.59
Value    
Beginning Balance $ 5.7 $ 7.5
Granted 2.3 2.7
Vested (2.9) (4.3)
Forfeited (0.5) (0.2)
Ending Balance $ 4.6 $ 5.7
Restricted Stock Units    
Shares    
Beginning Balance (in shares) 58,404 78,366
Granted (in shares) 63,446 24,790
Vested (in shares) (18,041) (79,460)
Forfeited (in shares) (16,460) (5,022)
Ending Balance (in shares) 94,654 58,404
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 51.03 $ 35.32
Granted (in usd per share) 39.29 58.77
Vested (in usd per share) 35.17 25.12
Forfeited (in usd per share) 30.90 49.00
Ending Balance (in usd per share) $ 48.42 $ 51.03
Value    
Beginning Balance $ 3.0 $ 2.8
Granted 2.4 1.5
Vested (0.6) (2.1)
Forfeited (0.5) (0.2)
Ending Balance $ 4.6 $ 3.0
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) 7,305 39,730
Weighted Average Grant Date Fair Value    
Granted (in usd per share) $ 34.63 $ 25.12
Value    
Granted $ 0.3 $ 1.0
LTIP Time-Based Vesting Units    
Shares    
Beginning Balance (in shares) 276,766 384,046
Granted (in shares) 342,349 174,340
Vested (in shares) (142,041) (279,123)
Forfeited (in shares) 0 (2,497)
Ending Balance (in shares) 477,074 276,766
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 42.21 $ 43.15
Granted (in usd per share) 30.08 44.08
Vested (in usd per share) 39.21 44.64
Forfeited (in usd per share) 0 46.08
Ending Balance (in usd per share) $ 34.40 $ 42.21
Value    
Beginning Balance $ 11.7 $ 16.6
Granted 10.3 7.7
Vested (5.5) (12.5)
Forfeited 0.0 (0.1)
Ending Balance $ 16.5 $ 11.7
LTIP Market-Based Vesting Units    
Shares    
Beginning Balance (in shares) 324,028 347,478
Granted (in shares) 282,034 125,550
Vested (in shares) (96,496) (298,000)
Forfeited (in shares) (56,102) 0
Ending Balance (in shares) 493,858 324,028
Weighted Average Grant Date Fair Value    
Beginning Balance (in usd per share) $ 42.84 $ 31.61
Granted (in usd per share) 39.29 54.77
Vested (in usd per share) 19.94 26.70
Forfeited (in usd per share) 4.56 0
Ending Balance (in usd per share) $ 47.76 $ 42.84
Value    
Beginning Balance $ 13.9 $ 11.0
Granted 11.1 6.9
Vested (1.9) (8.0)
Forfeited (0.3) 0.0
Ending Balance $ 23.6 $ 13.9
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) 40,394 149,000
Weighted Average Grant Date Fair Value    
Granted (in usd per share) $ 19.94 $ 26.70
Value    
Granted $ 0.8 $ 4.0