Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock-based compensation awards
Vesting period of awards issued prior to 2015, after the date of grant (in years)	3 years
Required minimum age of a participant upon separation from service to meet the criteria for Long Service Separation (in years)	55 years
Minimum term of service to meet criteria for Long Service Separation (in years)	5 years
Requisite service period prior to 2015 grant (in months)	6 months
Term life of SARs and option awards (in years)	10 years
Term life of vested options/SARs from separation date (in years)	5 years
Stock-based compensation expense, before tax (in dollars)	$ 135	$ 53
Granted, Stock options (in shares)	7,939,497	4,448,218
Weighted-Average Fair Value Per Award, Stock options (in dollars per share)	$ 23.61	$ 29.52
Weighted-Average Grant Date Stock Price (in dollars per share)	$ 83.34	$ 96.31
Assumptions used in determining the fair value of the stock-based awards
Weighted-average dividend yield (as a percent)	2.27%	2.15%
Weighted-average volatility (as a percent)	28.40%	28.20%
Volatilities, low end of range (as a percent)	19.90%	18.40%
Volatilities, high end of range (as a percent)	35.90%	36.20%
Risk-free interest rates, low end of range (as a percent)	0.22%	0.12%
Risk-free interest rates, high end of range (as a percent)	2.08%	2.60%
Weighted-average expected lives (in years)	8 years	8 years
Unrecognized compensation cost related to nonvested stock-based compensation awards (in dollars)	$ 369
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)	1,805,044	1,429,512
Weighted-Average Fair Value Per Award, RSUs (in dollars per share)	$ 77.47	$ 89.18
Weighted-Average Grant Date Stock Price (in dollars per share)	$ 82.99	$ 96.31
2015 Grant
Stock-based compensation awards
Graded vesting period of awards granted (in years)	3 years
2015 Grant | Percentage of award vested on first anniversary of grant date
Stock-based compensation awards
Portion of the award vested on each anniversary of the grant date	33.33%
2015 Grant | Percentage of award vested on second anniversary of grant date
Stock-based compensation awards
Portion of the award vested on each anniversary of the grant date	33.33%
2015 Grant | Percentage of award vested on third anniversary of grant date
Stock-based compensation awards
Portion of the award vested on each anniversary of the grant date	33.33%