Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2015 USD ($)	Nov. 01, 2014 USD ($)	Oct. 31, 2015 USD ($) segments	Nov. 01, 2014 USD ($)	Jan. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segments			2
Business segment information
Total assets	$ 15,175	$ 15,762	$ 15,175	$ 15,762	$ 15,256
Total revenue	8,819	9,032	25,905	26,130
Operating income (loss)	230	205	604	640
Other income (expense)
Gain on sale of investments	0	5	2	7
Investment income and other	3	0	14	10
Interest expense	(20)	(22)	(60)	(68)
Earnings from continuing operations before income tax (benefit) expense	213	188	560	589
Domestic [Member]
Business segment information
Total assets	13,823	13,137	13,823	13,137	12,998
Total revenue	8,090	7,992	23,858	23,358
Operating income (loss)	244	204	857	688
International [Member]
Business segment information
Total assets	1,352	2,625	1,352	2,625	$ 2,258
Total revenue	729	1,040	2,047	2,772
Operating income (loss)	$ (14)	$ 1	$ (253)	$ (48)