XML 50 R38.htm IDEA: XBRL DOCUMENT v3.7.0.1
Incentive Plans (Summary of Stock-Based Award Activity) (Detail) - $ / shares
6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Restricted Stock Shares [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding 1,182,231 1,157,270
Awards granted [1] 439,484  
Awards cancelled / forfeited (59,614)  
Lapse of restrictions (354,909)  
Weighted average grant date fair value per share/unit $ 121.81  
Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding 0 20,000
Options exercised (20,000)  
Performance Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding 396,591 331,526
Awards granted [2] 108,398  
Awards cancelled / forfeited (43,333)  
Lapse of restrictions 0  
Weighted average grant date fair value per share/unit $ 183.48  
[1]
Weighted average grant date fair value per share is $121.81
[2]
Weighted average grant date fair value per unit is $183.48