Benefit Plans - Net Periodic Benefit Expense and Contribution for Defined Benefit Pension Plans and Other Postretirement Benefit Plans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 07, 2013	Sep. 08, 2012	Sep. 07, 2013	Sep. 08, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost
Interest cost	28	28	65	66
Expected return on assets	(33)	(31)	(76)	(72)
Amortization of prior service benefit
Amortization of net actuarial loss	24	26	55	60
Net periodic benefit expense	19	23	44	54
Contributions to benefit plans	(21)	(15)	(92)	(81)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			1	1
Interest cost	1	1	2	3
Expected return on assets
Amortization of prior service benefit	(3)	(3)	(7)	(7)
Amortization of net actuarial loss	1	1	3	3
Net periodic benefit expense	(1)	(1)	(1)
Contributions to benefit plans	$ (2)	$ (2)	$ (3)	$ (3)