Retirement Benefit Plans (Level 3 Investment Assets) (Details) $ in Millions |
12 Months Ended | |
|---|---|---|
|
Feb. 03, 2018
USD ($)
manager
|
Jan. 28, 2017
USD ($)
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
| Number of hedge fund managers (more than) | manager | 30 | |
| Corporate bonds [Member] | ||
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
| Balance, beginning of year | $ 7 | $ 5 |
| Transfers, net | 0 | |
| Realized gains | (7) | 3 |
| Unrealized gains/(losses) | 6 | (4) |
| Purchases and issuances | 6 | 15 |
| Sales, maturities and settlements | (2) | (12) |
| Balance, end of year | 10 | 7 |
| Corporate loans [Member] | ||
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
| Balance, beginning of year | 0 | 3 |
| Transfers, net | 0 | |
| Realized gains | 0 | 0 |
| Unrealized gains/(losses) | 0 | 0 |
| Purchases and issuances | 4 | 0 |
| Sales, maturities and settlements | 0 | (3) |
| Balance, end of year | $ 4 | $ 0 |