Retirement Benefit Plans (Net Periodic Expense) (Details) - USD ($)
$ in Millions |
3 Months Ended |
6 Months Ended |
|
Jul. 30, 2016 |
Aug. 01, 2015 |
Jul. 30, 2016 |
Aug. 01, 2015 |
Jan. 30, 2016 |
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
|
|
|
|
|
|
| Net periodic benefit expense/(income) |
$ 2
|
$ (16)
|
[1] |
$ 4
|
$ (35)
|
|
| Other Postretirement Benefit Plan [Member] |
|
|
|
|
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
|
|
|
|
|
|
| Net periodic benefit expense/(income) |
(4)
|
(2)
|
|
(8)
|
(4)
|
|
| Defined Benefit Plan, Accumulated Benefit Obligation |
1
|
|
|
1
|
|
$ 8
|
| Primary Pension Plan |
|
|
|
|
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
|
|
|
|
|
|
| Service cost |
14
|
18
|
|
28
|
35
|
|
| Interest cost |
38
|
49
|
|
76
|
98
|
|
| Other cost |
0
|
3
|
|
0
|
3
|
|
| Expected return on plan assets |
(54)
|
(89)
|
|
(108)
|
(178)
|
|
| Amortization of prior service cost/(credit) |
2
|
2
|
|
4
|
4
|
|
| Net periodic benefit expense/(income) |
0
|
(17)
|
|
0
|
(38)
|
|
| Supplemental Pension Plans |
|
|
|
|
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
|
|
|
|
|
|
| Interest cost |
2
|
1
|
|
4
|
3
|
|
| Net periodic benefit expense/(income) |
2
|
1
|
|
4
|
3
|
|
| Primary and Supplemental Pension Plans Total |
|
|
|
|
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
|
|
|
|
|
|
| Service cost |
14
|
18
|
|
28
|
35
|
|
| Interest cost |
40
|
50
|
|
80
|
101
|
|
| Other cost |
0
|
3
|
|
0
|
3
|
|
| Expected return on plan assets |
(54)
|
(89)
|
|
(108)
|
(178)
|
|
| Amortization of prior service cost/(credit) |
2
|
2
|
|
4
|
4
|
|
| Net periodic benefit expense/(income) |
$ 2
|
$ (16)
|
|
$ 4
|
$ (35)
|
|
|
|