Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Derivatives Fair Value [Line Items]
Derivatives assets	$ 14.5	$ 13.0
Derivatives liabilities	631.2	605.9
Interest Rate Swap [Member] | Long Term Debt [Member] | Non Derivative Designated As Hedging Instrument [Member] | Net Investment Hedging [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	614.9	600.4
Derivatives Designated as Accounting Hedges [Member]
Derivatives Fair Value [Line Items]
Derivatives assets		0.5
Derivatives liabilities	12.2	3.5
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets		0.5
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	12.2	3.5
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	14.5	12.5
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Accounts Payable And Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	$ 4.1	$ 2.0