Financial Instruments Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Jul. 31, 2016	Jan. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 8.5	$ 8.3
Derivative Liabilities	9.0	6.4
Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Derivative, notional amount	445.7	142.4
Net gain expected to be recognized in next 12 months	4.7
Foreign currency contracts | Designated as hedging instrument | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6.7	3.4
Foreign currency contracts | Designated as hedging instrument | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	8.0	3.4
Foreign currency contracts | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative, notional amount	88.7	231.6
Foreign currency contracts | Derivatives not designated as hedging instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1.8	4.9
Foreign currency contracts | Derivatives not designated as hedging instruments | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 1.0	$ 3.0