Long-Term Debt (Debt Issues) (Details) - USD ($)
$ in Millions
 12 Months Ended
Jan. 30, 2016
Jan. 31, 2015
Sep. 30, 2014
Debt Instrument [Line Items]      
Total debt, excluding unamortized debt issuance costs, capital leases and note payable $ 4,830 $ 5,350  
Total debt, excluding unamortized debt issuance costs, capital leases and note payable 4,769 5,255  
Unamortized Debt Issuance Expense (61) (95)  
Less: current maturities 101 28 [1]  
Total long-term debt, excluding capital leases and note payable $ 4,668 $ 5,227 [1]  
Weighted-average interest rate at year end 6.50% 6.40%  
Weighted-average maturity (in years) 13 years    
5.65% Senior Notes Due 2020(1) (2)      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 5.65% 5.65%  
Unsecured Long-term Debt, Noncurrent [2],[3] $ 400 $ 400  
Unamortized Debt Issuance Expense [2],[3] $ (4) $ (5)  
5.75% Senior Notes Due 2018(1) (3)      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 5.75% 5.75%  
Unsecured Long-term Debt, Noncurrent [2],[4] $ 300 $ 300  
Unamortized Debt Issuance Expense [2],[3] $ (1) $ (1)  
6.375% Senior Notes Due 2036(1) (4)      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 6.375% 6.375%  
Unsecured Long-term Debt, Noncurrent [2],[5] $ 400 $ 400  
Unamortized Debt Issuance Expense [2],[3] $ (6) $ (7)  
6.9% Notes Due 2026      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 6.90% 6.90%  
Unsecured Long-term Debt, Noncurrent $ 2 $ 2  
7.125% Debentures Due 2023      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 7.125% 7.125%  
Unsecured Long-term Debt, Noncurrent $ 10 $ 10  
7.4% Debentures Due 2037(5)      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 7.40% 7.40%  
Unsecured Long-term Debt, Noncurrent [6] $ 326 $ 326  
Unamortized Debt Issuance Expense [2],[3] $ (1) $ (1)  
7.625% Notes Due 2097      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 7.625% 7.625%  
Unsecured Long-term Debt, Noncurrent $ 500 $ 500  
7.65% Debentures Due 2016      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 7.65% 7.65%  
Unsecured Long-term Debt, Noncurrent $ 78 $ 78  
7.95% Debentures Due 2017      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 7.95% 7.95%  
Unsecured Long-term Debt, Noncurrent $ 220 $ 220  
2013 Term Loan Facility (7)      
Debt Instrument [Line Items]      
Secured Debt [7] 2,194 2,216  
Unamortized Debt Issuance Expense [2],[3] (41) (58)  
2014 Term Loan (8)      
Debt Instrument [Line Items]      
Secured Debt [8]   498  
Unamortized Debt Issuance Expense [2],[3] (13)    
Total debt, excluding unamortized debt issuance costs, capital leases and note payable      
Debt Instrument [Line Items]      
Total debt, excluding unamortized debt issuance costs, capital leases and note payable $ 4,830 $ 5,350  
Senior notes      
Debt Instrument [Line Items]      
Debt repurchase provision, percentage of outstanding principal 101.00%    
Debt repurchase provision, required beneficial ownership change 50.00%    
8.125% Senior Notes Due 2019 (6)      
Debt Instrument [Line Items]      
Debt instrument, stated interest rate (percent) 8.125% 8.125% 8.125%
Unsecured Long-term Debt, Noncurrent $ 400 [9] $ 400 [9] $ 400
Unamortized Debt Issuance Expense [2],[3] $ (8) $ (10)  
[1] As Adjusted
[2] These debt issuances contain a change of control provision that would obligate us, at the holders’ option, to repurchase the debt at a price of 101%. These provisions trigger if there were a beneficial ownership change of 50% or more of our common stock.
[3] and $5 million of unamortized debt issue costs in 2015 and 2014, respectively.
[4] and $1 million of unamortized debt issue costs in 2015 and 2014, respectively.
[5] and $7 million of unamortized debt issue costs in 2015 and 2014, respectively.
[6] and $1 million of unamortized debt issue costs in 2015 and 2014, respectively.
[7] and $58 million of unamortized debt issue costs in 2015 and 2014, respectively.
[8] of unamortized debt issue costs in 2014.
[9] and $10 million of unamortized debt issue costs in 2015 and 2014, respectively.