Share-Based Compensation (Stock Option Activity) (Details 3) - Stock option [Member] - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, at the beginning of the period (in shares)	7.2
Weighted average exercise price (in dollars per share)	$ 81.11	$ 65.07
Weighted average remaining contractual life of options outstanding	6 years 8 months 12 days	6 years 8 months 12 days
Granted (in shares)	1.6
Weighted average exercise price granted (in dollars per share)	$ 128.58
Exercised (in shares)	(1.4)
Weighted average exercise price exercised (in dollars per share)	$ 50.50
Forfeited (in shares)	(0.1)
Weighted average exercise price forfeited (in dollars per share)	$ 106.17
Exercisable (in shares)	4.2
Weighted average exercise price exercisable (in dollars per share)	$ 59.02
Weighted average remaining contractual life of options exercisable	5 years 4 months 24 days
Aggregate intrinsic value of options exercisable	$ 201
Intrinsic value of options exercised	$ 111	$ 243	$ 299
Outstanding, at the end of the period (in shares)	7.3	7.2
Aggregate intrinsic value of options outstanding (in dollars)	$ 222	$ 485