Retirement Benefit Plans (Accumulated Other Comprehensive (Loss)/Income) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Jan. 30, 2016 |
Jan. 31, 2015 |
|
| Supplemental Employee Retirement Plan [Member] | ||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
| Net loss/(gain) | $ 13 | $ 17 |
| Prior service cost/(credit) | (4) | (4) |
| Defined Benefit Plan, Accumulated Other Comprehensive Income, before Tax, Total | 9 | 13 |
| Pension Plan [Member] | ||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
| Net loss/(gain) | 333 | 213 |
| Prior service cost/(credit) | 57 | 65 |
| Defined Benefit Plan, Accumulated Other Comprehensive Income, before Tax, Total | 390 | $ 278 |
| Defined Benefit Plan, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year | $ 8 |