Derivative instruments and hedging activities - Impact of derivatives on interest expense (Details) - Interest Expense [Member] - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Derivatives not designated for hedge accounting:
Total Interest expense		$ (1)	$ 11	$ (15)	$ 4
Not Designated as Hedging Instrument [Member] | Intercompany Loan [Member]
Derivatives not designated for hedge accounting:
Loss on the change in fair value - Derivatives not designated for hedge accounting	[1]	(2)	3	(2)	4
Not Designated as Hedging Instrument [Member] | Merchandise Purchases Program [Member]
Derivatives not designated for hedge accounting:
Loss on the change in fair value - Derivatives not designated for hedge accounting		$ 1	$ 8	$ (13)	$ 0

[1] (Losses) gains related to our short-term intercompany loan foreign exchange contracts were recorded in Interest expense, in addition to the corresponding foreign exchange gains and losses related to our short-term, cross-currency intercompany loans. As a result of the Chapter 11 bankruptcy filing, we no longer had foreign currency forward contracts to economically hedge intercompany loans. Therefore, nominal foreign exchange net gains were recorded in Other income, net on our short-term, cross currency loans subsequent to the Chapter 11 bankruptcy filing.