Segment Reporting Segment Assets (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Assets		$ 38,879	$ 38,632
Corporate Assets		3,518	4,417
Total Assets - Discontinued Operations	[1]	0	65,634
Assets		$ 42,397	$ 108,683

[1] See Note 5 - Divestitures and Other Transactions, for additional information on discontinued operations.