Shareholders' Equity (Details) - USD ($)	3 Months Ended		9 Months Ended		40 Months Ended	41 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Aug. 31, 2015	Sep. 30, 2015	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Shares purchased (in shares)						73,800,000
Total cost of shares purchased			$ 1,150,000,000			$ 5,500,000,000
Weighted average shares outstanding
Shares for basic earnings per share (in shares)	280,900,000	292,300,000	283,200,000	298,100,000
Common stock equivalents (in shares)	2,900,000	3,800,000	2,700,000	3,500,000
Shares for diluted earnings per share (in shares)	283,800,000	296,100,000	285,900,000	301,600,000
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 (up to)								$ 5,000,000,000.0
Shares purchased (in shares)	6,300,000	5,800,000	11,700,000	20,400,000
Average price per share of stock repurchased	$ 95.75	$ 86.07	$ 98.00	$ 85.73
Total cost of shares purchased	$ 600,000,000	$ 500,000,000	$ 1,150,000,000	$ 1,800,000,000
Share Repurchase Program of 2014 [Member]
Common Stock Programs
Share repurchase authorization limit (up to)							$ 5,000,000,000.0
Share repurchase, remaining authorization limit	$ 4,500,000,000		$ 4,500,000,000			$ 4,500,000,000
2012 - Share Repurchase Program [Member]
Common Stock Programs
Total cost of shares purchased					$ 5,000,000,000