Income Tax Provision (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Federal	$ 132.3	$ 196.8	$ 130.1
Foreign	44.5	40.8	32.3
State	20.9	21.5	15.8
Current provision, total	197.7	259.1	178.2
Federal	(62.1)	(18.3)	(17.8)
Foreign	4.4	(26.5)	(3.9)
State	(7.7)	(0.3)	(5.2)
Deferred (benefit) provision, total	(65.4)	(45.1)	(26.9)
Income tax provision	$ 132.3	$ 214.0	$ 151.3