Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
Retirement Benefit Plans (Level 3 Investment Assets) (Details)
$ in Millions
12 Months Ended
Jan. 30, 2016
USD ($)
manager
Jan. 31, 2015
USD ($)
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 $ 11
Transfers, net 0  
Realized gains (3) 0
Unrealized gains/(losses) 2 (1)
Purchases and issuances 1 5
Sales, maturities and settlements (2) (8)
Balance, end of year 5 7
Corporate loans [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of year 5 6
Transfers, net 0  
Realized gains 0 0
Unrealized gains/(losses) 0 0
Purchases and issuances 0 4
Sales, maturities and settlements (2) (5)
Balance, end of year 3 5
Hedge Funds [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of year 314 153
Transfers, net 0  
Realized gains 3 13
Unrealized gains/(losses) (1) (4)
Purchases and issuances 119 467
Sales, maturities and settlements (221) (315)
Balance, end of year 214 314
Private Equity Funds [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of year 281 298
Transfers, net 0  
Realized gains 41 57
Unrealized gains/(losses) (17) (8)
Purchases and issuances 18 31
Sales, maturities and settlements (75) (97)
Balance, end of year 248 281
Private real estate [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of year 153 204
Transfers, net 0  
Realized gains (23) 3
Unrealized gains/(losses) 38 17
Purchases and issuances 2 3
Sales, maturities and settlements (19) (74)
Balance, end of year $ 151 $ 153