Goodwill and Intangible Assets (Goodwill Rollforward) (Details) - USD ($)	3 Months Ended	9 Months Ended		12 Months Ended
	Oct. 31, 2014	Oct. 02, 2015	Oct. 31, 2014	Jan. 30, 2015
Goodwill [Roll Forward]
Beginning balance			$ 1,693,000,000	$ 1,693,000,000
Goodwill impairment charges	$ 0	$ 0	(486,000,000)	(486,000,000)
Adjustments		0
Ending balance		1,207,000,000		1,207,000,000
NSS
Goodwill [Roll Forward]
Beginning balance			788,000,000	788,000,000
Goodwill impairment charges				0
Adjustments		0
Ending balance		788,000,000		788,000,000
HES
Goodwill [Roll Forward]
Beginning balance			$ 905,000,000	905,000,000
Goodwill impairment charges				(486,000,000)
Adjustments		0
Ending balance		$ 419,000,000		$ 419,000,000