Stockholders' Equity (Reclassifications Out of Accumulated Other Comprehensive Income/ (Loss) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Nov. 01, 2014
Nov. 02, 2013
Nov. 01, 2014
Nov. 02, 2013
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax $ 16 $ 43 $ 49 $ 131
Total, net of tax 9 26 29 80
Reclassification out of Accumulated Other Comprehensive Income [Member]
       
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Total reclassifications 9 26 29 80
Reclassification out of Accumulated Other Comprehensive Income [Member] | Total Amortization Of Retirement Benefit Plans, Net Of Tax [Member]
       
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Total, net of tax 9 26 29 80
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension [Member]
       
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Amortization of retirement benefit plans, Actuarial loss/(gain) 16 [1] 44 [1] 49 [1] 132 [1]
Amortization of retirement benefit plans, Prior service cost/(credit) 1 [1] 1 [1] 5 [1] 4 [1]
Reclassification out of Accumulated Other Comprehensive Income [Member] | SG&A [Member]
       
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Amortization of retirement benefit plans, Prior service cost/(credit) (2) [1] (2) [1] (6) [1] (6) [1]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax 0 [1] (1) [1] 0 [1] (1) [1]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Income Tax (Expense)/Benefit [Member]
       
Other Comprehensive Income (Loss), Net of Tax [Abstract]        
Amortization of retirement benefit plans, Tax (expense)/benefit $ 6 $ 16 $ 19 $ 49
[1] These accumulated other comprehensive components are included in the computation of net periodic benefits expense/(income). See Note 8 for additional details.