Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense, before tax (in dollars)	$ 53	$ 49
Stock-based compensation awards
Granted, Stock options (in shares)	4,448,218	4,276,060
Fair Value Per Award, Stock options (in dollars per share)	$ 29.52	$ 28.34
Stock price on the date of grant (in dollars per share)	$ 96.31	$ 89.75
Assumptions used in determining the fair value of the stock-based awards
Weighted-average dividend yield (as a percent)	2.15%	2.13%
Weighted-average volatility (as a percent)	28.20%	30.60%
Volatilities, low end of range (as a percent)	18.40%	23.40%
Volatilities, high end of range (as a percent)	36.20%	40.60%
Risk-free interest rates, low end of range (as a percent)	0.12%	0.16%
Risk-free interest rates, high end of range (as a percent)	2.60%	1.88%
Weighted-average expected lives (in years)	8 years	8 years
Unrecognized compensation cost related to nonvested stock-based compensation awards (in dollars)	$ 395
Term of amortization of unrecognized compensation cost over weighted-average remaining requisite service periods (in years)	2 years 5 months
RSUs
Stock-based compensation awards
Granted (in shares)	1,429,512	1,614,870
Fair Value Per Award (in dollars per share)	$ 89.18	$ 84.05