Dispositions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Nov. 01, 2013	Oct. 31, 2014	Nov. 01, 2013
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total loss from discontinued operations before income taxes	$ (1)	$ 19	$ (12)	$ 144
Impairment of assets			9
SAIC
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	8	598	34	2,712
Cost of revenues	8	533	34	2,446
Selling, general and administrative expenses	0	22	0	42
Separation transaction and restructuring expenses	0	20	0	55
Operating income	0	23	0	169
Other Disposals
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	5	7	25	25
Cost of revenues	2	10	19	27
Selling, general and administrative expenses	5	1	24	20
Intangible asset impairment charges	0	0	3	2
Operating income	(2)	(4)	(21)	(24)
Non-operating income (expense)	1	0	9	(1)
Total loss from discontinued operations before income taxes	(1)	(4)	(12)	(25)
Impairment of assets			$ 9