Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.4.0.3
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation expense $ 9.8 $ 11.1  
Unrecognized compensation cost on non-vested stock awards $ 41.3    
Unrecognized compensation cost on non-vested stock awards, weighted-average period of recognition 1 year 4 months 24 days    
Total intrinsic value of awards exercised for options and SARs $ 5.9 17.6  
Total vesting date fair value of stock units 0.1 $ 0.1  
Unrealized excess tax benefits $ 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 $ 21.69 $ 12.18