Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 29, 2017	Jul. 30, 2016
Numerator:
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 63	$ (107)	$ 168	$ (47)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	(8)	(659)	(928)	(678)
Net income (loss)	$ 55	$ (766)	$ (760)	$ (725)
Denominator:
Weighted-average common shares outstanding	655	648	654	647
Effect of dilutive securities
Restricted shares (including performance-based awards)	5	0	4	0
Weighted-average common shares outstanding assuming dilution	660	648	658	647
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	13	31	26	34
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.10	$ (0.17)	$ 0.26	$ (0.07)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	(0.02)	(1.01)	(1.41)	(1.05)
Earnings Per Share, Diluted	0.08	(1.18)	(1.15)	(1.12)
Earnings Per Share, Basic [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share	0.10	(0.17)	0.26	(0.07)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	(0.02)	(1.01)	(1.42)	(1.05)
Earnings Per Share, Basic	$ 0.08	$ (1.18)	$ (1.16)	$ (1.12)