Organizational Changes (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended	12 Months Ended
	Apr. 28, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Amount of other increase (decrease) in additional paid in capital (APIC) due to a return of capital	$ 2,700							$ 2,737
Gain on sale of equity method investment recognized as capital contribution		$ 1,100	$ 750	$ 202
Income Tax Expense (Benefit)						$ (338)	$ 153	$ (738)
Spinoff [Member]
Restructuring Cost and Reserve [Line Items]
Amount of other increase (decrease) in additional paid in capital (APIC) due to a return of capital					$ 3,400
Gain on sale of equity method investment recognized as capital contribution					703
Income Tax Expense (Benefit)					$ 643