Retirement Benefit Plans (Net Periodic Expense) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Apr. 28, 2012
Apr. 30, 2011
Service cost $ 23 $ 23
Interest cost 65 65
Expected return on assets (94) (96)
Net amortization 64 37
Net periodic plan expense/(income) 58 29
Benefits Plan Primary Plan [Member]
   
Service cost 23 22
Interest cost 62 62
Expected return on assets (94) (96)
Net amortization 58 34
Net periodic plan expense/(income) 49 22
Benefits Supplemental Plan [Member]
   
Service cost   1
Interest cost 3 3
Net amortization 6 3
Net periodic plan expense/(income) 9 7
Postretirement Health and Welfare Plan [Member]
   
Service cost      
Interest cost      
Expected return on assets      
Net amortization (4) (6)
Net periodic plan expense/(income) $ (4) $ (6)