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Share-based Compensation - Schedule of Changes in Time-Based, Performance-Based and Market-Based Restricted Stock Awards and Stock Units (Detail) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Time-based Restricted Stock Awards and Stock Units [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Outstanding at December 31, 2018 357,592    
Granted (in shares) 319,189    
Vested and settled (in shares) (157,053)    
Cancelled (in shares) (51,000)    
Outstanding at December 31, 2019 468,728 357,592  
Outstanding at December 31, 2018 $ 49.77    
Granted (in dollars per share) 52.48    
Vested and settled (in dollars per share) 46.82    
Cancelled (in dollars per share) 52.85    
Outstanding at December 31, 2019 $ 51.96 $ 49.77  
Performance-based Restricted Stock Awards and Stock Units [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Outstanding at December 31, 2018 102,155    
Granted (in shares) 0 0 0
Vested and settled (in shares) (102,155)    
Outstanding at December 31, 2019   102,155  
Outstanding at December 31, 2018 $ 33.12    
Vested and settled (in dollars per share) $ 33.12    
Outstanding at December 31, 2019   $ 33.12  
Market-based Restricted Stock Units [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Outstanding at December 31, 2018 271,295    
Granted (in shares) 60,722    
Cancelled (in shares) (74,855)    
Outstanding at December 31, 2019 257,162 271,295  
Outstanding at December 31, 2018 $ 57.44    
Granted (in dollars per share) 65.27    
Cancelled (in dollars per share) 15.92    
Outstanding at December 31, 2019 $ 60.08 $ 57.44