Benefit Plans - Net Periodic Benefit Expense and Contributions for Defined Benefit Pension Plans and Other Postretirement Benefit Plans (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 12, 2015	Sep. 06, 2014	Sep. 12, 2015	Sep. 06, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	24	27	57	66
Expected return on assets	(32)	(36)	(76)	(83)
Amortization of prior service benefit	0	0	0	0
Amortization of net actuarial loss	18	15	42	34
Net periodic benefit expense (income)	10	6	23	17
Contributions to benefit plans	(1)	(22)	(27)	(67)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	2	2
Expected return on assets	0	0	0	0
Amortization of prior service benefit	(4)	(4)	(8)	(8)
Amortization of net actuarial loss	1	1	3	2
Net periodic benefit expense (income)	(2)	(2)	(3)	(4)
Contributions to benefit plans	$ 0	$ (1)	$ (11)	$ (1)