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Stock-Based Compensation - Summary of Stock Awards Outstanding (Details) - $ / shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Restricted Stock Units (RSUs)      
Nonvested RSUs/PSUs      
Balance at period start (in shares) 600,240    
Granted (in shares) 183,093    
Vested (in shares) (260,307) (204,665) (166,197)
Forfeited (in shares) (21,923)    
Balance at period end (in shares) 501,103 600,240  
Weighted- Average Grant-Date Fair Value      
Balance at period start (in dollars per share) $ 148.29    
Granted (in dollars per share) 240.09    
Vested (in dollars per share) 121.84    
Forfeited (in dollars per share) 201.84    
Balance at period end (in dollars per share) $ 193.23 $ 148.29  
Performance Share Units (PSUs)      
Nonvested RSUs/PSUs      
Balance at period start (in shares) 240,100    
Granted (in shares) 50,100    
Vested (in shares) (78,727) (235,935) (331,099)
Unearned (in shares) (4,143)    
Forfeited (in shares) (4,400)    
Balance at period end (in shares) 202,930 240,100  
Weighted- Average Grant-Date Fair Value      
Balance at period start (in dollars per share) $ 171.34    
Granted (in dollars per share) 240.72    
Earned (in dollars per share) 147.75    
Unearned (in dollars per share) 147.75    
Forfeited (in dollars per share) 207.40    
Balance at period end (in dollars per share) $ 197.33 $ 171.34