Income Taxes - Income Before Income Taxes and Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income before income taxes
Domestic	$ 1,333	$ 1,371	$ 1,308
Foreign	1,148	1,149	1,218
Income before income tax expense (benefit)	2,481	2,520	2,526
Current tax expense:
Federal	189	140	266
State	124	107	92
Foreign	241	226	268
Current tax expense	554	473	626
Deferred tax expense (benefit):
Federal	(21)	29	(677)
State	(4)	9	33
Foreign	(8)	(11)	(10)
Deferred tax expense (benefit)	(33)	27	(654)
Total income tax expense (benefit)	$ 521	$ 500	$ (28)