Benefit Plans (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Sep. 10, 2011	Sep. 11, 2010	Sep. 10, 2011	Sep. 11, 2010
Benefit Plans (Textual) [Abstract]
Contribution to Pension Plans			$ 45
Contribution to other postretirement benefits plan			1
Contribution to Multi-Employer Plans			71	73
Reduction in postretirement benefit obligation			39
Pension Benefits [Member]
Net periodic benefit expense (income) for defined benefit pension plans and other postretirement benefit plans
Service cost	2	2	5	4
Interest cost	32	32	74	74
Expected return on assets	(29)	(28)	(67)	(66)
Amortization of net actuarial loss	21	14	50	35
Net periodic benefit expense	26	20	62	47
Other Postretirement Benefits [Member]
Net periodic benefit expense (income) for defined benefit pension plans and other postretirement benefit plans
Service cost			1	1
Interest cost	2	2	4	4
Amortization of prior service benefit	(1)	(1)	(3)	(3)
Amortization of net actuarial loss	1		2	1
Net periodic benefit expense	$ 2	$ 1	$ 4	$ 3