Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Interest Rate Swaps	Mar. 31, 2013 Not Designated as Hedging Instrument Foreign Exchange Swaps	Mar. 31, 2012 Not Designated as Hedging Instrument Foreign Exchange Swaps	Mar. 31, 2013 Other Current Assets Liabilities Fair Value, Measurements, Recurring Not Designated as Hedging Instrument Less Than Six Months Foreign Exchange Swaps	Dec. 31, 2012 Other Current Assets Liabilities Fair Value, Measurements, Recurring Not Designated as Hedging Instrument Less Than Six Months Foreign Exchange Swaps
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative notional volume, amount after offsetting swaps		$ 532.8	$ 1,103.2	$ 532.8	$ 569.9
Derivative asset, amount after offsetting swaps				1.8	0.6
Derivative liability, amount after offsetting swaps				0.6	0.6
Interest rate derivative asset	$ 60