Benefit Plans - Net Periodic Benefit Expense (Income) for Defined Benefit Pension and Other Postretirement Benefit Plans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 10, 2011	Sep. 08, 2012	Sep. 08, 2012	Sep. 10, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 3	$ 6	$ 5
Interest cost	32	31	73	74
Expected return on assets	(29)	(34)	(79)	(67)
Amortization of net actuarial loss	21	27	64	50
Net periodic benefit expense	26	27	64	62
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			1	1
Interest cost	2	2	3	4
Amortization of prior service benefit	(1)	(3)	(7)	(3)
Amortization of net actuarial loss	1	1	3	2
Net periodic benefit expense	$ 2			$ 4