Benefit Plans (Actuarially Determined Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 29, 2011	Oct. 30, 2010	Oct. 29, 2011	Oct. 30, 2010
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 25	$ 25	$ 76	$ 75
Interest cost	40	40	120	119
Expected return on assets	(61)	(55)	(185)	(164)
Recognition of net actuarial (gain) loss	22	15	66	45
Amortization of prior service cost	(1)	(1)	(1)	(1)
Total	25	24	76	74
Supplementary Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	4	4
Interest cost	9	9	27	27
Recognition of net actuarial (gain) loss	2	1	6	3
Amortization of prior service cost	0	0	(1)	(1)
Total	12	11	36	33
Postretirement Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	3	4	10	11
Recognition of net actuarial (gain) loss	(1)	(2)	(4)	(4)
Amortization of prior service cost	0	0	0	0
Total	$ 2	$ 2	$ 6	$ 7