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Retirement-Related Benefits (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Jan. 31, 2018 | Jan. 31, 2017
Contribution expense from retirement plans [Line Items] |  |
Defined contribution plan, employer matching contribution, percent of match | 100.00% |
Defined contribution plan, employer matching contribution, percent of employees' gross pay | 6.00% |
Vesting percentage of matching contribution to eligible associates | 100.00% |
Defined contribution plan, maximum annual contributions per employee, percent | 50.00% |
United Kingdom | Deferred income taxes and other |  |
Contribution expense from retirement plans [Line Items] |  |
Assets for plan benefits, defined benefit plan | $ 97 |
Liability, defined benefit plan, noncurrent |  | $ 129
Japan | Deferred income taxes and other |  |
Contribution expense from retirement plans [Line Items] |  |
Liability, defined benefit plan, noncurrent | $ 184 | $ 203

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