Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.5.0.2
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation expense $ 9.8 $ 10.3 $ 30.3 $ 34.2  
Unrecognized compensation cost on non-vested stock awards 59.5   $ 59.5    
Unrecognized compensation cost on non-vested stock awards, weighted-average period of recognition     1 year 6 months    
Total intrinsic value of awards exercised for options and SARs 17.9 4.2 $ 32.0 23.8  
Total vesting date fair value of stock units 0.2 $ 0.3 2.0 $ 1.3  
Unrealized excess tax benefits $ 25.4   $ 25.4   $ 25.4
SARs [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Weighted-average grant date fair value of SARs granted $ 32.06 $ 24.11 $ 29.49 $ 12.88