Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Retirement Benefit Plans (Level 3 Investment Assets) (Details)
$ in Millions
12 Months Ended
Jan. 28, 2017
USD ($)
manager
Jan. 30, 2016
USD ($)
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 $ 5 $ 7
Transfers, net 0  
Realized gains 3 (3)
Unrealized gains/(losses) (4) 2
Purchases and issuances 15 1
Sales, maturities and settlements (12) (2)
Balance, end of year 7 5
Corporate loans [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of year 3 5
Transfers, net 0  
Realized gains 0 0
Unrealized gains/(losses) 0 0
Purchases and issuances 0 0
Sales, maturities and settlements (3) (2)
Balance, end of year $ 0 $ 3