Benefit Plans (Details) (USD $) In Millions	3 Months Ended
	Jun. 18, 2011	Jun. 19, 2010
Benefit Plans (Textuals) [Abstract]
Contribution to Pension Plans	$ 30
Contribution to other postretirement benefits plan	2
Contribution to Multi-Employer Plans	40	42
Pension Benefits [Member]
Net periodic benefit expense (income) for defined benefit pension plans and other postretirement benefit plans
Service cost	3	2
Interest cost	43	42
Expected return on assets	(39)	(38)
Amortization of net actuarial loss	29	21
Net periodic benefit expense	36	27
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
Amortization of prior service benefit	(2)	(2)
Amortization of net actuarial loss	1	1
Net periodic benefit expense	$ 2	$ 2