Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 29, 2017	Jul. 30, 2016
Total Retirement Expense	$ 11	$ 12	$ 20	$ 25
Settlement charges	51	6	51	19
Nonqualified Plan [Member]
Defined contribution plans expense	0	1	0	1
Qualified Plan [Member]
Defined contribution plans expense	24	25	45	49
Pension Plan [Member]
Service cost	2	1	3	2
Interest cost	27	28	54	56
Expected return on assets	(57)	(58)	(113)	(114)
Recognition of net actuarial (gain) loss	8	7	16	15
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(20)	(22)	(40)	(41)
Supplemental Employee Retirement Plan [Member]
Service cost	0	0	0	0
Interest cost	5	6	11	12
Recognition of net actuarial (gain) loss	2	2	4	4
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	7	8	15	16
Other Postretirement Benefits Plan [Member]
Service cost	0	0	0	0
Interest cost	2	1	3	3
Recognition of net actuarial (gain) loss	(1)	(1)	(2)	(2)
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 1	$ 0	$ 1	$ 1