Benefit Plans (Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 28, 2012	Apr. 30, 2011
Pension Contributions		$ 225
Pension Plan [Member]
Service cost	28	26
Interest cost	39	40
Expected return on assets	(63)	(62)
Amortization of net actuarial (gain) loss	35	21
Amortization of prior service credit	0	0
Total net periodic benefit cost	39	25
Supplemental Employee Retirement Plans, Defined Benefit [Member]
Service cost	2	1
Interest cost	8	9
Amortization of net actuarial (gain) loss	4	2
Amortization of prior service credit	0	0
Total net periodic benefit cost	14	12
Amount Recognized In Net Periodic Postretirement Benefit Cost [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Service cost	0	0
Interest cost	3	4
Amortization of net actuarial (gain) loss	(1)	(1)
Amortization of prior service credit	0	0
Total net periodic benefit cost	$ 2	$ 3