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Stock-Based Compensation - Summary of Stock Awards (Details) - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Non-Vested Shares      
Non-Vested Shares, Beginning Balance (in shares) 922,530    
Non-Vested Shares, Awarded (in shares) 443,101    
Non-Vested Shares, Vested (in shares) (389,484)    
Non-Vested Shares, Cancelled (in shares) (33,629)    
Non-Vested Shares, Ending Balance (in shares) 942,518 922,530  
Weighted Average Grant Date Fair Value      
Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share) $ 33.11    
Weighted Average Grant Date Fair Value, Awarded (in dollars per share) 38.51 $ 32.42 $ 38.52
Weighted Average Grant Date Fair Value, Vested (in dollars per share) 35.45    
Weighted Average Grant Date Fair Value, Cancelled (in dollars per share) 39.68    
Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share) $ 35.29 $ 33.11  
Performance Shares      
Weighted Average Grant Date Fair Value      
Maximum shares that could vest (percent) 200.00%    
Maximum number that could vest (in shares) 1,255,445 1,171,334