Components of Net Periodic Pension Benefit Cost and Postretirement Benefit Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 27, 2012	Oct. 29, 2011
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 3	$ 10	$ 9
Interest cost	7	8	21	24
Expected return on plan assets	(10)	(10)	(30)	(30)
Amortization of net loss (gain)	4	4	12	11
Net benefit expense (income)	4	5	13	14
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Amortization of net loss (gain)	(1)	(2)	(3)	(4)
Net benefit expense (income)	$ (1)	$ (2)	$ (3)	$ (4)