Comprehensive Income - Schedule of Components of Other Comprehensive Loss and Income Tax (Benefit) Expense Allocated to Each Component (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive (loss) income, Before Tax Amount	$ (36.8)	$ (34.1)	$ (25.3)	$ (26.3)
Other comprehensive (loss) income, Income Tax Expense	(13.0)	1.1	(3.0)	5.7
Other comprehensive (loss) income, Net of Tax Amount	(23.8)	(35.2)	(22.3)	(32.0)
Translation adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive (loss) income, Before Tax Amount	(4.4)	(37.5)	(9.0)	(42.5)
Other comprehensive (loss) income, Income Tax Expense		0.0	0.0	0.0
Other comprehensive (loss) income, Net of Tax Amount	(4.4)	(37.5)	(9.0)	(42.5)
Adjustment for net periodic pension and other postretirement benefits plan cost
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive (loss) income, Before Tax Amount	(32.4)	3.4	(16.3)	16.1
Other comprehensive (loss) income, Income Tax Expense	(13.0)	1.2	(3.0)	5.7
Other comprehensive (loss) income, Net of Tax Amount	$ (19.4)	2.2	$ (13.3)	10.4
Change in fair value of derivatives
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive (loss) income, Before Tax Amount				0.1
Other comprehensive (loss) income, Income Tax Expense		(0.1)		0.0
Other comprehensive (loss) income, Net of Tax Amount		$ 0.1		$ 0.1