Fair Value of Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Oct. 31, 2011	Jan. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 12.5	$ 5.1
Derivative Liabilities	3.1	1.2
Designated as Hedging Instrument | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	7.4	5.1
Designated as Hedging Instrument | Foreign exchange contracts | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	3.1	1.2
Derivatives Not Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 5.1