Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015
Total Retirement Expense	$ 9	$ 20	$ 34	$ 61
Settlement charges	62	0	81	0
Pension Plan [Member]
Service cost	1	2	3	5
Interest cost	27	35	83	103
Expected return on assets	(56)	(59)	(170)	(176)
Recognition of net actuarial (gain) loss	7	9	22	28
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	(21)	(13)	(62)	(40)
Supplemental Employee Retirement Plan [Member]
Service cost	0	0	0	0
Interest cost	5	7	17	23
Recognition of net actuarial (gain) loss	3	3	7	8
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	8	10	24	31
Other Postretirement Benefit Plan [Member]
Service cost	0	0	0	0
Interest cost	1	2	4	6
Recognition of net actuarial (gain) loss	(1)	0	(3)	0
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	0	2	1	6
Defined Contribution Qualified Plan [Member]
Defined contribution plans expense	22	22	71	69
Non qualified defined contribution plan [Member]
Defined contribution plans expense	$ 0	$ 1	$ 1	$ 1