XML 141 R96.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation - Summary Information for Restricted Stock Awards and Incentive Compensation Stock Awards (Detail) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Restricted Stock - Service Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Awards, January 1, 2019 278,147    
Number of Awards, Awarded 86,922    
Number of Awards, Distributed (171,689)    
Number of Awards, Forfeited (9,441)    
Number of Awards, December 31, 2019 183,939 278,147  
Weighted-Average Grant-Date Fair Value, January 1, 2019 $ 158.29    
Weighted-Average Grant-Date Fair Value, Awarded 196.91 $ 211.03 $ 213.76
Weighted-Average Grant-Date Fair Value, Distributed 148.72    
Weighted-Average Grant-Date Fair Value, Forfeited 166.51    
Weighted-Average Grant-Date Fair Value, December 31, 2019 $ 185.06 $ 158.29  
Restricted Stock - Performance Based Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Awards, January 1, 2019 151,939    
Number of Awards, Awarded 49,644    
Number of Awards, Distributed (54,424)    
Number of Awards, Forfeited (5,329)    
Number of Awards, Adjustment for performance (17,609)    
Number of Awards, December 31, 2019 124,221 151,939  
Weighted-Average Grant-Date Fair Value, January 1, 2019 $ 174.74    
Weighted-Average Grant-Date Fair Value, Awarded 192.27 $ 212.12 207.73
Weighted-Average Grant-Date Fair Value, Distributed 133.73    
Weighted-Average Grant-Date Fair Value, Forfeited 205.21    
Weighted-Average Grant-Date Fair Value, Adjustment for performance 133.77    
Weighted-Average Grant-Date Fair Value, December 31, 2019 $ 204.21 $ 174.74  
Incentive Compensation Stock Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Awards, January 1, 2019 35,376    
Number of Awards, Awarded 21,883    
Number of Awards, Distributed (15,948)    
Number of Awards, Forfeited (1,727)    
Number of Awards, December 31, 2019 39,584 35,376  
Weighted-Average Grant-Date Fair Value, January 1, 2019 $ 206.55    
Weighted-Average Grant-Date Fair Value, Awarded 192.27 $ 212.12 $ 208.68
Weighted-Average Grant-Date Fair Value, Distributed 206.23    
Weighted-Average Grant-Date Fair Value, Forfeited 205.54    
Weighted-Average Grant-Date Fair Value, December 31, 2019 $ 198.83 $ 206.55