Retirement Benefit Plans (Postretirement Plan (Income)) (Details) - USD ($) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Jun. 07, 2005 |
Feb. 03, 2018 |
Jan. 28, 2017 |
Jan. 30, 2016 |
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
| Net periodic benefit expense/(income) | $ (21) | $ (19) | $ (162) | |
| Other Postretirement Benefit Plan, Defined Benefit [Member] | ||||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
| Reduction of plan benefits, employee age (post-age) | 65 years | |||
| Reduction of plan benefits (percent) | 45.00% | |||
| Net periodic benefit expense/(income) | $ 17 | 7 | ||
| Accumulated postretirement benefit obligation | $ 8 | |||