Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.3.0.814
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation expense $ 10.3 $ 11.0 $ 34.2 $ 34.4  
Unrecognized compensation cost on non-vested stock awards 62.4   $ 62.4    
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 4.2 2.4 $ 23.8 37.4  
Total vesting date fair value of stock units 0.3 $ 0.2 1.3 $ 8.7  
Unrealized excess tax benefits $ 24.1   $ 24.1   $ 23.6
SARs [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Weighted-average grant date fair value of SARs granted $ 24.11 $ 20.88 $ 12.88 $ 25.71