Shareholders' Equity (Details) - USD ($)	3 Months Ended						9 Months Ended		90 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Feb. 28, 2017	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Total cost of shares purchased	$ 350,000,000	$ 1,056,000,000	$ 101,000,000	$ 301,000,000	$ 402,000,000	$ 553,000,000
Weighted average shares outstanding
Basic weighted average ordinary shares outstanding (in shares)	236,900,000			244,000,000.0			239,900,000	246,200,000
Dilutive effect of potentially issuable shares (in shares)	2,200,000			1,600,000			2,000,000.0	1,500,000
Diluted weighted average ordinary shares outstanding (in shares)	239,100,000			245,600,000			241,900,000	247,700,000
Number of shares excluded from the calculation of diluted earnings per share (in shares)	0			0			0	0
2012 - Share Repurchase Program
Common Stock Programs
Share repurchase authorization limit (up to)	$ 15,000,000,000.0						$ 15,000,000,000.0		$ 15,000,000,000.0	$ 5,000,000,000.0	$ 5,000,000,000.0	$ 5,000,000,000.0
Share repurchase, remaining authorization limit (in shares)	$ 2,500,000,000						$ 2,500,000,000		$ 2,500,000,000
Shares purchased (in shares)	1,800,000			2,100,000			8,200,000	8,800,000	126,500,000
Total cost of shares purchased	$ 350,000,000			$ 300,000,000			$ 1,500,000,000	$ 1,250,000,000	$ 12,500,000,000