Benefit Plans (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Feb. 25, 2012	Feb. 26, 2011	Feb. 27, 2010
Pension Benefits [Member]
Net Periodic Benefit Cost
Service cost	$ 9	$ 8	$ 6
Interest cost	138	137	138
Expected return on assets	(125)	(123)	(129)
Amortization of net actuarial loss	93	65	10
Settlement	1	9	2
Net periodic benefit cost	116	96	27
Other changes in plan assets and benefit obligations recognized in other comprehensive income loss
Net actuarial loss (gain)	464	(12)	(42)
Amortization of net actuarial loss	(93)	(65)	(10)
Total recognized in other comprehensive income (loss)	371	(77)	(52)
Total recognized in net periodic benefit expense and other comprehensive income (loss)	487	19	(25)
Other Postretirement Benefits [Member]
Net Periodic Benefit Cost
Service cost	2	2	2
Interest cost	7	8	8
Amortization of prior service benefit	(9)	(6)	(6)
Amortization of net actuarial loss	4	2	2
Net periodic benefit cost	4	6	6
Other changes in plan assets and benefit obligations recognized in other comprehensive income loss
Prior service benefit	(52)
Amortization of prior service benefit	9	6	6
Net actuarial loss (gain)	16	13	10
Amortization of net actuarial loss	(4)	(2)	(2)
Total recognized in other comprehensive income (loss)	(31)	17	14
Total recognized in net periodic benefit expense and other comprehensive income (loss)	$ (27)	$ 23	$ 20