Derivative Instruments and Hedging Activities (Details) (Interest rate swaps, Designated as Hedging Instrument, USD $) In Millions, unless otherwise specified	Oct. 31, 2014	Jan. 31, 2014
Notes payable and long-term debt, net of current portion
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Liability	$ 2	$ 0
Notes payable and long-term debt, net of current portion | Notes Which Mature In December 2020
Derivative [Line Items]
Hedged instrument, face amount	450
Stated interest rate	4.45%
Other assets
Derivative [Line Items]
Derivative asset	$ 2	$ 0