Annual report pursuant to Section 13 and 15(d)

Retirement Benefit Plans (Level 3 Investment Assets) (Details)

v3.8.0.1
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