Income Taxes - Earnings Before Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ (2,784)	$ (4,274)	$ (2,678)
Foreign	11,210	9,471	10,405
Total earnings before income tax expense	$ 8,426	$ 5,197	$ 7,727