Investments, Loans and LT Receivables - Financial Info (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity Method Investment, Summarized Financial Information [Abstract]
Revenues	$ 11,654	$ 11,554	$ 10,149
Income before income taxes	3,660	(2,875)	660
Net income (loss)	3,244	(1,431)	$ 799
Current assets	3,285	2,920
Noncurrent assets	41,563	42,693
Current liabilities	2,625	2,453
Noncurrent liabilities	$ 23,874	$ 25,522

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