Fair Value Disclosures (REIT Assets Measured on Recurring Basis) (Details) (USD $)
In Millions, unless otherwise specified
Apr. 28, 2012
Jan. 28, 2012
Apr. 30, 2011
Fair Value, Inputs, Level 1 [Member]
     
REIT assets $ 379 $ 336 $ 289
Fair Value, Inputs, Level 2 [Member]
     
REIT assets         
Fair Value, Inputs, Level 3 [Member]
     
REIT assets