Shareholders' Equity (Details) (USD $)	1 Months Ended	3 Months Ended				9 Months Ended				30 Months Ended
	Apr. 30, 2012	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014
Common Stock Programs
Total cost of shares purchased						$ 1,750,000,000
Weighted average shares outstanding
Shares for basic earnings per share (in shares)		292,300,000	[1]	309,500,000	[1]	298,100,000	[1]	313,200,000	[1]
Common stock equivalents (in shares)		3,800,000		3,400,000		3,500,000		3,500,000
Shares for diluted earnings per share (in shares)		296,100,000		312,900,000		301,600,000		316,700,000
Number of participating securities (in shares)		2,900,000		3,800,000		3,100,000		4,000,000
Number of shares excluded from the calculation of diluted earnings per share		0		0		0		0
2012 - Share Repurchase Program [Member]
Common Stock Programs
Share repurchase authorization limit	5,000,000,000
Shares purchased (in shares)		5,800,000		7,300,000		20,400,000		15,800,000		56,700,000
Average price per share of stock repurchased		$ 86.07		$ 68.33		$ 85.73		$ 64.79
Total cost of shares purchased		500,000,000		500,000,000		1,800,000,000		1,000,000,000		3,900,000,000
Share repurchase, remaining authorization limit						$ 1,100,000,000

[1] Includes 2.9 million and 3.8 million of participating securities for the three months ended September 30, 2014 and 2013, respectively, and 3.1 million and 4.0 million of participating securities for the nine months ended September 30, 2014 and 2013, respectively.