Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v3.10.0.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Income Tax Disclosure [Abstract]      
Effective income tax rate 26.40% 29.20%  
Federal statutory income tax rate 21.00% 35.00%  
Unrecognized tax benefits $ 25.2   $ 25.2
Unrecognized Tax Benefits that Would Impact Effective Tax Rate 8.5   8.5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued 2.5   2.1
Liability for Uncertainty in Income Taxes, Noncurrent $ 27.7   $ 27.3