Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Income Tax Disclosure [Abstract]    
Income taxes (benefit) expense $ 39.1 $ 9.4
Effective income tax rate 28.90% 10.30%
Excess tax benefits on share-based compensation included in discrete events $ 2.4 $ 19.4
Total amount of unrecognized tax benefits, including related interest and penalties 67.0  
Unrecognized tax benefits excluding interest and penalties that if recognized would affect the effective tax rate 45.8  
Total accrued interest for tax contingencies 10.2  
Total accrued penalties for tax contingencies 1.8  
Amount of unrecognized tax benefits that could decrease within the next 12 months 2.8  
Decrease in unrecognized tax benefits due to the settlement of audits or resolution of administrative or judicial proceedings 0.5  
Decrease in unrecognized tax benefits expiration of statute of limitations $ 2.3  
Effective tax rate applied 21.00%