Shareholders' Equity (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended		63 Months Ended
	Jul. 31, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Feb. 28, 2017	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Shares purchased (in shares)						99,300,000
Total cost of shares purchased				$ 1,160,000,000		$ 8,300,000,000
Treasury stock acquired, additional transaction costs		$ 5,100,000		$ 5,800,000
Weighted average shares outstanding
Shares for basic earnings per share (in shares)		262,400,000	268,000,000	263,600,000	269,900,000
Dilutive effect of potentially issuable shares (in shares)		0	1,800,000	2,100,000	1,800,000
Shares for diluted earnings per share (in shares)		262,400,000	269,800,000	265,700,000	271,700,000
Number of shares excluded from the calculation of diluted earnings per share (in shares)		1,900,000	0	200,000	300,000
Share Repurchase Program of 2014
Common Stock Programs
Share repurchase authorization limit (up to)							$ 5,000,000,000.0	$ 5,000,000,000.0
Share repurchase, remaining authorization limit (shares)		$ 6,700,000,000		$ 6,700,000,000		$ 6,700,000,000
2012 - Share Repurchase Program
Common Stock Programs
Share repurchase authorization limit (up to)									$ 5,000,000,000.0
Shares purchased (in shares)		8,000,000	0	9,100,000	7,700,000
Average price per share of stock repurchased (in usd per share)		$ 128.54		$ 126.85	$ 97.92
Total cost of shares purchased		$ 1,000,000,000		$ 1,200,000,000	$ 750,000,000
Subsequent Event | 2012 - Share Repurchase Program
Common Stock Programs
Shares purchased (in shares)	450,000
Average price per share of stock repurchased (in usd per share)	$ 133.24
Total cost of shares purchased	$ 60,000,000