Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Derivatives assets	$ 13.0	$ 7.6
Derivatives liabilities	605.9	427.3
Non-Derivative Designated As Hedging Instrument [Member] | Net Investment Hedging [Member] | Long-Term Debt [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	600.4	421.9
Derivatives Designated as Accounting Hedges [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	0.5	7.6
Derivatives liabilities	3.5	4.6
Derivatives Designated as Accounting Hedges [Member] | Cross-Currency Swap [Member] | Other Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities		3.8
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	0.5	7.0
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	3.5	0.8
Derivatives Designated as Accounting Hedges [Member] | Net Investment Hedging [Member] | Foreign Exchange Forwards [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets		0.6
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forwards [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	12.5
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forwards [Member] | Accounts Payable and Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	$ 2.0	$ 0.8