Retirement Benefit Plans (Obligations and Funded Status) (Details) (USD $)
In Millions, unless otherwise specified
 0 Months Ended 12 Months Ended
Oct. 15, 2011
Jan. 28, 2012
Jan. 29, 2011
Jan. 30, 2010
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]        
Service cost   $ 90 $ 89 $ 83
Interest cost   260 262 270
Enhanced Retirement Benefits, Amount 176      
Defined Benefit Plan, Curtailments 1      
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]        
Beginning balance   5,251    
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]        
Balance at measurement date   5,176 5,251  
Benefits Plan Primary Plan [Member]
        
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]        
Beginning balance   4,488 4,326  
Service cost   88 88 80
Interest cost   247 248 253
Enhanced Retirement Benefits, Amount 133 133    
Actuarial loss/(gain)   612 80  
Benefits (paid)   (271) (254)  
Balance at measurement date   5,297 4,488 4,326
Defined Benefit Plan, Accumulated Benefit Obligation   4,900 4,100  
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]        
Beginning balance   5,251 4,314  
Company contributions     392  
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]        
Actual return on plan assets   196 799  
Benefits (paid)   (271) (254)  
Balance at measurement date   5,176 5,251 4,314
Funded status of the plan   (121) 763  
Benefits Supplemental Plan [Member]
        
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]        
Beginning balance   222 257  
Service cost   2 1 3
Interest cost   13 14 17
Enhanced Retirement Benefits, Amount   43    
Defined Benefit Plan, Plan Amendments   3    
Actuarial loss/(gain)   65 (18)  
Benefits (paid)   (39) (32)  
Balance at measurement date   309 222 257
Defined Benefit Plan, Accumulated Benefit Obligation   272 194  
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]        
Company contributions   39 32  
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]        
Benefits (paid)   (39) (32)  
Funded status of the plan   (309) (222)  
Current Portion of Pension Plan Liability Accrued   45 28  
Other Postretirement Benefit Plans, Defined Benefit [Member]
        
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]        
Beginning balance   15 18  
Interest cost   1 1 1
Participant contributions   11 11  
Actuarial loss/(gain)   9 (3)  
Benefits (paid)   (12) (12)  
Balance at measurement date   24 15 18
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]        
Participant contributions   11 11  
Company contributions   1 1  
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]        
Benefits (paid)   (12) (12)  
Funded status of the plan   (24) (15)  
Current Portion of Pension Plan Liability Accrued   $ 3