Schedule of Stock-Based Compensation and Related Tax Benefits Recognized (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefits recognized from stock-based compensation	$ 22	$ 21	$ 21
Continuing Operations
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense recorded in continuing operations	56	53	55
Continuing Operations | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense recorded in continuing operations	10	9	11
Continuing Operations | Vesting Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense recorded in continuing operations	46	44	43
Continuing Operations | Vested Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense recorded in continuing operations	0	0	1
Discontinued Operations
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense recorded in continuing operations	$ 21	$ 31	$ 30