Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
 3 Months Ended
May 04, 2019
May 05, 2018
Income Tax Contingency [Line Items]    
Income tax expense/(benefit) $ 1 $ (1)
Increase to tax valuation allowance for deferred tax assets 23  
Valuation allowance increase due to increase in NOL carryforwards 35  
Valuation allowance increase attributable to the loss in OCI $ 3  
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.  
Income tax benefit due to release of valuation allowance $ 2  
Net operating loss carryforwards 2,200  
Valuation allowance decrease due to lease accounting tax benefit (15)  
Federal, State And Foreign [Member]    
Income Tax Contingency [Line Items]    
State and foreign tax expenses (2)  
Amortization of certain indefinite lived intangible assets [Member]    
Income Tax Contingency [Line Items]    
State and foreign tax expenses (1)  
Federal [Member]    
Income Tax Contingency [Line Items]    
Federal unused interest deductions that do not expire subject to interest limitation 274  
Tax credit carryforwards 69  
Federal tax authority [Member]    
Income Tax Contingency [Line Items]    
Valuation allowance 576  
State Tax Authority [Member]    
Income Tax Contingency [Line Items]    
Valuation allowance $ 249