Equity Investments and Loans (Summarized Financial Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Revenues	$ 2,753	$ 2,294	$ 1,406
Income before income taxes	1,894	1,536	853
Net income	1,832	1,518	778
Current assets	642	751	577
Noncurrent assets	12,072	9,561	8,571
Current liabilities	662	3,008	354
Noncurrent liabilities	$ 4,322	$ 496	$ 3,001