Stock Based Compensation (Stock Option Activity) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 28, 2017 USD ($) $ / shares shares
Share-based Compensation [Abstract]
Outstanding, beginning of period, shares | shares	18,829,800
Outstanding, beginning of period, weighted average exercise price | $ / shares	$ 41.92
Granted, shares | shares	3,886,800
Granted, weighted average exercise price | $ / shares	$ 42.97
Canceled or forfeited, shares | shares	(1,116,600)
Canceled or forfeited, weighted average exercise price | $ / shares	$ 51.33
Exercised, shares | shares	(1,122,100)
Exercised, weighted average exercise price | $ / shares	$ 31.30
Outstanding, end of period, shares | shares	20,477,900
Outstanding, end of period, weighted average exercise price | $ / shares	$ 42.18
Exercisable, end of period, shares | shares	12,541,500
Exercisable, end of period, weighted average exercise price | $ / shares	$ 36.48
Exercisable, end of period, weighted average remaining contractual life (years)	4 years 1 month 6 days
Exercisable, end of period, aggregate intrinsic value | $	$ 46
Options expected to vest, shares | shares	6,657,500
Options expected to vest, weighted average exercise price | $ / shares	$ 51.07
Options expected to vest, weighted average remaining contractual life (years)	8 years 3 months 18 days
Options expected to vest, aggregate intrinsic value | $	$ 0