Earnings/(Loss) per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 9 Months Ended
Oct. 29, 2016
Oct. 31, 2015
Oct. 29, 2016
Oct. 31, 2015
Earnings Per Share [Abstract]        
Net income/(loss) $ (67) $ (115) [1] $ (191) $ (382) [1]
Weighted average common shares outstanding (basic shares) 308.3 306.0 [1] 307.8 305.8 [1]
Weighted average shares assuming dilution (diluted shares) 308.3 306.0 [1] 307.8 305.8 [1]
Basic (in dollars per share) $ (0.22) $ (0.38) [1] $ (0.62) $ (1.25) [1]
Diluted (in dollars per share) $ (0.22) $ (0.38) [1] $ (0.62) $ (1.25) [1]
Stock options, restricted stock awards and warrant 32.9 32.0 33.7 31.8
[1] As Adjusted