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. 10, 2016	Sep. 12, 2015	Sep. 10, 2016	Sep. 12, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 0	$ 0	$ 0	$ 0
Interest cost	20	24	46	57
Expected return on assets	(33)	(32)	(77)	(76)
Amortization of prior service benefit	0	0	0	0
Amortization of net actuarial loss	10	18	24	42
Net periodic benefit expense (income)	(3)	10	(7)	23
Contributions to benefit plans	(1)	(1)	(2)	(27)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	0	0	0	0
Interest cost	0	1	1	2
Expected return on assets	0	0	0	0
Amortization of prior service benefit	(3)	(4)	(8)	(8)
Amortization of net actuarial loss	0	1	1	3
Net periodic benefit expense (income)	(3)	(2)	(6)	(3)
Contributions to benefit plans	$ 0	$ 0	$ 0	$ (11)