Shareholders' Equity (Details) - USD ($) shares in Millions	3 Months Ended		84 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Feb. 28, 2017	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Shares purchased (in shares)			118.9
Total cost of shares purchased	$ 101,000,000	$ 553,000,000	$ 11,100,000,000
Weighted average shares outstanding
Basic weighted average ordinary shares outstanding (in shares)	242.2	248.5
Dilutive effect of potentially issuable shares (in shares)	1.5	1.7
Diluted weighted average ordinary shares outstanding (in shares)	243.7	250.2
Number of shares excluded from the calculation of diluted earnings per share (in shares)	0.1	0.1
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)	$ 3,900,000,000		$ 3,900,000,000
2012 - Share Repurchase Program
Common Stock Programs
Share repurchase authorization limit (up to)						$ 5,000,000,000.0
Shares purchased (in shares)	0.6	3.9
Total cost of shares purchased	$ 100,000,000	$ 550,000,000