Shareholders' Equity (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended		72 Months Ended
	Jul. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Feb. 28, 2017	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Shares purchased (in shares)						115,000,000
Total cost of shares purchased				$ 955,000,000	$ 1,160,000,000	$ 10,500,000,000
Weighted average shares outstanding
Basic weighted average ordinary shares outstanding (in shares)		246,000,000	262,400,000	247,200,000	263,600,000
Dilutive effect of potentially issuable shares (in shares)		1,400,000	0	1,600,000	2,100,000
Diluted weighted average ordinary shares outstanding (in shares)		247,400,000	262,400,000	248,800,000	265,700,000
Number of shares excluded from the calculation of diluted earnings per share (in shares)		0	1,900,000	0	200,000
Share Repurchase Program of 2014
Common Stock Programs
Share repurchase authorization limit (up to)		$ 15,000,000,000.0		$ 15,000,000,000.0			$ 5,000,000,000.0	$ 5,000,000,000.0
Share repurchase, remaining authorization limit (in shares)		$ 4,500,000,000		$ 4,500,000,000
2012 - Share Repurchase Program
Common Stock Programs
Share repurchase authorization limit (up to)									$ 5,000,000,000.0
Shares purchased (in shares)	500,000	2,800,000	8,000,000	6,700,000	9,100,000
Total cost of shares purchased	$ 60,000,000	$ 400,000,000	$ 1,030,000,000	$ 950,000,000	$ 1,154,000,000