|
Retirement Benefits Plans (Estimated Future Benefit Payments) (Details) (USD $)
In Millions, unless otherwise specified |
Jan. 31, 2015
|
|---|---|
| Pension Plan [Member] | |
| Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract] | |
| 2015 | $ 388 |
| 2016 | 333 |
| 2017 | 333 |
| 2018 | 334 |
| 2019 | 336 |
| 2020-2024 | 1,682 |
| Supplemental Pension Plans [Member] | |
| Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract] | |
| 2015 | 16 |
| 2016 | 44 |
| 2017 | 22 |
| 2018 | 15 |
| 2019 | 14 |
| 2020-2024 | 67 |
| Other Postretirement Benefit Plan, Defined Benefit [Member] | |
| Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract] | |
| 2015 | 1 |
| 2016 | 1 |
| 2017 | 1 |
| 2018 | 1 |
| 2019 | 1 |
| 2020-2024 | $ 5 |