Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.21.1
Share-Based Compensation - Additional Information (Detail) - USD ($)
shares in Thousands, $ in Millions
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 13.3 $ 10.3
Unrecognized compensation cost on non-vested stock awards $ 118.6  
Unrecognized compensation cost on non-vested stock awards, weighted-average period of recognition 2 years 1 month 6 days  
Total vesting date fair value of stock units $ 35.5 $ 9.6
SARs [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
SARs granted 0 0
Total intrinsic value of awards exercised for SARs $ 13.8 $ 1.6