Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax	$ 0.1	$ 1.4
Gains on cash flow hedges - Tax		(0.5)
Gains on cash flow hedges - Net of Tax	0.1	0.9
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(1.4)	(2.4)
Amortization of actuarial losses and prior service costs included in net income - Tax	0.4	0.9
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	(1.0)	(1.5)
Income Loss Attributable to Reclassification Out Of AOCI Net Of Tax	(0.9)	(0.6)
Operating Expense [Member]
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(0.9)	(1.5)
SG&A Expense [Member]
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(0.5)	(0.9)
Currency Swap [Member] | Other Nonoperating Income (Expense) [Member]
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax	$ 0.1	1.5
Interest Rate Contract [Member] | Interest Expense [Member]
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax		$ (0.1)