CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings [Member]
Long-term Debt, Fair Value	$ 3,100
Beginning Balance (in shares) at Jan. 31, 2015		367		(166)
Beginning Balance at Jan. 31, 2015	5,991	$ 4	$ 2,743	$ (8,744)	$ (20)	$ 12,008
Comprehensive income (loss)	379				2
Net income	377					377
Stock options and awards, (in shares)		3		0
Stock options and awards	157		183
Stock Issued During Period, Value, Stock Options Exercised				$ (26)
Dividends paid ($1.35 per common share)	(264)		0	$ 3		(267)
Treasury stock purchases, (in shares)				(13)
Treasury stock purchases	(789)			$ (789)
Ending Balance (in shares) at Oct. 31, 2015		370		(179)
Ending Balance at Oct. 31, 2015	5,474	$ 4	$ 2,926	$ (9,556)	$ (18)	$ 12,118
Long-term Debt, Fair Value	$ 2,900