Annual report pursuant to Section 13 and 15(d)

Income Taxes - Changes Occurred in Amount of Unrecognized Tax Benefits (Detail)

v3.8.0.1
Income Taxes - Changes Occurred in Amount of Unrecognized Tax Benefits (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Beginning balance of unrecognized tax benefits $ 50.5 $ 49.4 $ 40.5
Additions for current year tax positions 13.0 9.3 11.3
Additions for prior year tax positions 3.6 2.0 2.5
Reductions for prior year tax positions (6.0) (4.7) (0.6)
Reductions for audit settlements (7.1)   (0.1)
Reductions for the expiration of statutes of limitation (6.2) (4.2) (2.8)
Changes due to foreign currency translation adjustments 2.8 (1.3) (1.4)
Ending balance of unrecognized tax benefits (excluding interest and penalties) 50.6 50.5 49.4
Interest and penalties associated with unrecognized tax benefits 11.4 11.5 8.6
Ending balance of unrecognized tax benefits (including interest and penalties) $ 62.0 $ 62.0 $ 58.0