Separation Transaction Expenses (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended	12 Months Ended
	Jan. 31, 2014	Nov. 01, 2013	Aug. 02, 2013	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Accounting Policies [Abstract]
Strategic advisory services				$ 7	$ 1
Legal and accounting services				2	0
Lease termination and facility consolidation expenses				46	2
Severance costs				10	8
Separation transaction expenses in operating income				65	11	0
Less: income tax benefit				(25)	(4)
Separation transaction expenses, net of tax	$ 7	$ 25	$ 33	$ 40	$ 7