Reclassification out of AOCI (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gains/(losses) on foreign currency translation adjustments
Liquidation of foreign subsidiary		$ 36.6	$ 0.1
Cash flow Hedges, net of tax:
Gains (losses) on cash flow hedges - Pre Tax	$ 11.5	(6.0)
Gains (losses) on cash flow hedges - Tax	(4.8)	2.3
Gains (losses) on cash flow hedges - Net of Tax	6.7	(3.7)
Gains on available for sale securities:
Gains on available for sale securities - Pre Tax	3.5		0.9
Total Gains on available for sale securities	3.5		0.9
Pension and other retirement benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(8.7)	(9.7)	(13.5)
Amortization of actuarial losses and prior service costs included in net income - Tax	3.3	3.7	5.2
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	(5.4)	(6.0)	(8.3)
Income (loss) attributable to reclassification out of AOCI - Net of Tax	(3.1)	26.9	(7.3)
Other Nonoperating Income (Expense) [Member]
Gains/(losses) on foreign currency translation adjustments
Liquidation of foreign subsidiary		36.6	0.1
Operating Expense [Member]
Pension and other retirement benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(5.5)	(5.8)	(8.5)
SG&A Expenses [Member]
Pension and other retirement benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(3.2)	(3.9)	(5.0)
Currency Swap [Member] | Other Nonoperating Income (Expense) [Member]
Cash flow Hedges, net of tax:
Gains (losses) on cash flow hedges - Pre Tax	12.6	(6.0)
Interest Rate Swap [Member] | Interest Income (Expense), Net [Member]
Cash flow Hedges, net of tax:
Gains (losses) on cash flow hedges - Pre Tax	(1.1)
Parent [Member]
Gains on available for sale securities:
Total Gains on available for sale securities	1.8		0.9
Pension and other retirement benefits, net of tax:
Income (loss) attributable to reclassification out of AOCI - Net of Tax	3.1	$ 26.9	(7.3)
Parent [Member] | Other Income [Member]
Gains on available for sale securities:
Gains on available for sale securities - Pre Tax	$ 1.8		$ 0.9