Stockholders' Equity (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 12 Months Ended
Apr. 28, 2012
Apr. 30, 2011
Apr. 28, 2012
Common Stock [Member]
Apr. 28, 2012
Additional Paid-in Capital [Member]
Apr. 28, 2012
Reinvested Earnings [Member]
Apr. 28, 2012
Accumulated Other Comprehensive (Loss)/Income [Member]
Jan. 28, 2012
Accumulated Other Comprehensive (Loss)/Income [Member]
Beginning balance, shares     215.9        
Beginning balance $ 4,010   $ 108 $ 3,699 $ 1,412 $ (1,209)  
Net income/(loss) (163) 64     (163)    
Other comprehensive income/(loss) 65 42       65  
Dividends declared, common (45)       (45)    
Stock-based compensation 69   1 68      
Stock-based compensation, shares     2.5        
Ending balance, shares     218.4        
Ending balance 3,936   109 3,767 1,204 (1,144) (1,209)
Net unrealized gain/(loss) on REITs, Net of Tax Amount           192 165
Net unrealized gain/(loss) on REITs, Deferred Tax Liability           107 91
Net actuarial gain/(loss) and prior service credit/(cost) - pension and postretirement plans, Net of Tax           (1,336) (1,374)
Accumulated other comprehensive income net actuarial gain/(loss) and prior service credit/(cost) pension and postretirement plans deferred tax           $ 852 $ 873