Retirement Benefit Plans (Postretirement Plan (Income)) (Details) - USD ($) $ in Millions |
12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
Jun. 07, 2005 |
Jan. 30, 2016 |
Jan. 31, 2015 |
Feb. 01, 2014 |
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| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||||||
| Net periodic benefit expense/(income) | $ (162) | $ 48 | [1] | $ 41 | [1] | |||
| 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) | 7 | 8 | $ 8 | |||||
| Accumulated postretirement benefit obligation | $ 8 | $ 11 | ||||||
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