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Amortization Expense (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Oct. 31, 2015
Nov. 01, 2014
Oct. 31, 2015
Nov. 01, 2014
Goodwill And Intangible Assets Disclosure [Line Items]        
Amortization expense $ 1 $ 2 $ 3 $ 5