Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Oct. 29, 2016
Oct. 31, 2015
[1]
Oct. 29, 2016
Oct. 31, 2015
[1]
Income Tax Contingency [Line Items]        
Income tax expense/(benefit) $ 3 $ (3) $ 7 $ 8
Increase to tax valuation allowance for deferred tax assets 30   $ 62  
Valuation allowance, methodologies and assumptions     In assessing the need for the valuation allowance, we considered both positive and negative evidence related to the likelihood of realization of the deferred tax assets. As a result of our periodic assessment, our estimate of the realization of deferred tax assets is solely based on the future reversals of existing taxable temporary differences and tax planning strategies that we would make use of to accelerate taxable income to utilize expiring NOL and tax credit carryforwards. Accordingly, in the third quarter and first nine months of 2016, the valuation allowance was increased by $30 million and $62 million, respectively, to offset the net deferred tax assets created in those periods relating primarily to the increase in NOL carryforwards.  
State Audit Settlement     2  
Net operating loss carryforwards 2,600   $ 2,600  
State and foreign [Member]        
Income Tax Contingency [Line Items]        
State and foreign tax expenses (3)   (10)  
Amortization of certain indefinite lived intangible assets [Member]        
Income Tax Contingency [Line Items]        
State and foreign tax expenses     (5)  
Settlement with Taxing Authority [Member]        
Income Tax Contingency [Line Items]        
State and foreign tax expenses 2   6  
Federal [Member]        
Income Tax Contingency [Line Items]        
Tax credit carryforwards 60   60  
Federal tax authority [Member]        
Income Tax Contingency [Line Items]        
Valuation allowance 845   845  
Net deferred tax asset, NOL and tax credit carryforwards 86   86  
State Tax Authority [Member]        
Income Tax Contingency [Line Items]        
Valuation allowance $ 242   $ 242  
[1] As Adjusted