|
Retirement Benefit Plans (Accumulated Other Comprehensive (Loss)/Income) (Details) (USD $)
In Millions, unless otherwise specified
|
12 Months Ended |
|
|
Jan. 28, 2012
|
Jan. 29, 2011
|
| Net loss/(gain) |
$ 2,285 |
$ 1,568 |
| Prior service cost/(credit) |
(38) |
(66) |
|
Benefits Plan Primary Plan [Member]
|
|
|
| Net loss/(gain) |
2,148 |
1,484 |
| Prior service cost/(credit) |
1 |
1 |
| Defined Benefit Plan, Accumulated Other Comprehensive Income, before Tax, Total |
2,149 |
1,485 |
| Defined Benefit Plan, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year |
231 |
|
|
Benefits Supplemental Plan [Member]
|
|
|
| Net loss/(gain) |
163 |
117 |
| Prior service cost/(credit) |
4 |
1 |
| Defined Benefit Plan, Accumulated Other Comprehensive Income, before Tax, Total |
167 |
118 |
| Defined Benefit Plan, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year |
22 |
|
|
Other Postretirement Benefit Plans, Defined Benefit [Member]
|
|
|
| Net loss/(gain) |
(5) |
(14) |
| Prior service cost/(credit) |
(43) |
(68) |
| Defined Benefit Plan, Accumulated Other Comprehensive Income, before Tax, Total |
(48) |
(82) |
| Defined Benefit Plan, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year |
$ (15) |
|