Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	Oct. 31, 2015	Jan. 31, 2015	Nov. 01, 2014	Feb. 01, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 501	$ 1,407	$ 631	$ 971
Long-term Debt, Excluding Current Maturities	2,792	2,780	2,779
Long Term Investments Fair Value	$ 2,900	$ 3,100	$ 3,100