Fair Value Disclosures (REIT Assets Measured on Recurring Basis) (Details) (Fair Value, Inputs, Level 1 [Member], USD $)
In Millions
Jul. 30, 2011
Jan. 29, 2011
Jul. 31, 2010
Fair Value, Inputs, Level 1 [Member]
     
REIT assets $ 300 $ 253 $ 224