Quarterly report pursuant to Section 13 or 15(d)

Accounting for Uncertainty in Income Taxes - Additional Information (Detail)

v3.8.0.1
Accounting for Uncertainty in Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
9 Months Ended 12 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]    
Liability for unrecognized tax $ 5.3 $ 4.6
Unrecognized tax favorable impact on effective tax rate 4.6  
Accrued interest and penalties applied to uncertain tax positions $ 2.1 $ 1.9