Summary of Significant Accounting Policies (Separation Transaction Expenses) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Nov. 01, 2013	Oct. 31, 2014	Nov. 01, 2013
Accounting Policies [Abstract]
Strategic advisory services	$ 0	$ 5	$ 0	$ 7
Legal and accounting services	0	1	0	1
Lease termination and facility consolidation expenses	0	17	1	40
Severance costs	0	2	0	10
Separation transaction and restructuring expenses in operating income (loss)	0	25	1	58
Less: income tax benefit	0	(10)	0	(23)
Separation transaction and restructuring expenses, net of tax	$ 0	$ 15	$ 1	$ 35