Shareholders' Equity (Details) - USD ($)	1 Months Ended		3 Months Ended			6 Months Ended		51 Months Ended
	Apr. 30, 2016	Aug. 31, 2015	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Shares purchased (in shares)								85,700,000
Total cost of shares purchased						$ 750,000,000		$ 6,700,000,000
Weighted average shares outstanding
Shares for basic earnings per share (in shares)			268,000,000		284,500,000	269,900,000	284,300,000
Common stock equivalents (in shares)			1,800,000		2,200,000	1,800,000	2,600,000
Shares for diluted earnings per share (in shares)			269,800,000		286,700,000	271,700,000	286,900,000
Number of shares excluded from the calculation of diluted earnings per share (in shares)			0			300,000
Decrease on prepaid pension				$ 267,000,000
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 (shares)			$ 3,300,000,000			$ 3,300,000,000		$ 3,300,000,000
2012 - Share Repurchase Program [Member]
Common Stock Programs
Share repurchase authorization limit (up to)										$ 5,000,000,000.0
Shares purchased (in shares)	600,000				3,000,000	7,700,000
Average price per share of stock repurchased (in usd per share)	$ 103.58				$ 100.92	$ 97.92
Total cost of shares purchased	$ 65,000,000	$ 5,000,000,000			$ 300,000,000	$ 750,000,000