Long-Term Debt (Details) - USD ($)
$ in Millions
Aug. 01, 2015
Jan. 31, 2015
Aug. 02, 2014
Debt Repurchase Provision, Debt Repurchase at a Percentage Price 101.00%    
Current maturities of long-term debt $ 28 $ 28 $ 28
Unamortized Debt Issuance Expense 83 95 96
Long-term Debt 5,253 5,255 5,255
Long-term debt, outstanding principal 5,336 5,350 5,351
Total long-term debt, excluding capital leases and note payable $ 5,225 5,227 5,227
Senior Notes 5.65% Due 2020 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 5.65%    
Unamortized Debt Issuance Expense [1] $ 4 5 5
Long-term Debt [1] 396 395 395
Long-term debt, outstanding principal [1] $ 400 400 400
Senior Notes 5.75% Due 2018 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 5.75%    
Unamortized Debt Issuance Expense [1] $ 1 1 2
Long-term Debt [1] 299 299 298
Long-term debt, outstanding principal [1] $ 300 300 300
Senior Notes 6.375% Due 2036 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 6.375%    
Unamortized Debt Issuance Expense [1] $ 6 7 7
Long-term Debt [1] 394 393 393
Long-term debt, outstanding principal [1] $ 400 400 400
Senior Notes 8.125% due 2019 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 8.125%    
Unamortized Debt Issuance Expense $ 9 10  
Long-term Debt 391 390 0
Long-term debt, outstanding principal $ 400 400 0
Medium-Term Notes 6.875% due 2015 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 6.875%    
Long-term Debt $ 0 0 200
Long-term debt, outstanding principal $ 0 0 200
Notes 6.9% Due 2026 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 6.90%    
Long-term Debt $ 2 2 2
Long-term debt, outstanding principal $ 2 2 2
Debentures 7.125% Due 2023 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 7.125%    
Long-term Debt $ 10 10 10
Long-term debt, outstanding principal $ 10 10 10
Debentures 7.4% Due 2037 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 7.40%    
Unamortized Debt Issuance Expense $ 1 1 1
Long-term Debt 325 325 325
Long-term debt, outstanding principal $ 326 326 326
Notes 7.625% Due 2097 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 7.625%    
Long-term Debt $ 500 500 500
Long-term debt, outstanding principal $ 500 500 500
Debentures 7.65% due 2016 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 7.65%    
Long-term Debt $ 78 78 200
Long-term debt, outstanding principal $ 78 78 200
Debentures 7.95% due 2017 [Member]      
Debt Instrument, Interest Rate, Stated Percentage 7.95%    
Long-term Debt $ 220 220 285
Long-term debt, outstanding principal 220 220 285
2013 Term Loan Facility [Member]      
Unamortized Debt Issuance Expense 50 58 67
Long-term Debt 2,155 2,158 2,161
Long-term debt, outstanding principal 2,205 2,216 2,228
2014 Term Loan [Member]      
Unamortized Debt Issuance Expense 12 13 14
Long-term Debt 483 485  
Long-term debt, outstanding principal $ 495 $ 498 $ 500
[1] These debt issuances contain change of control provisions that would obligate us, at the holders’ option, to repurchase the debt at a price equal to 101% of the principal amount of the debt.