Investments in Unconsolidated Entities - Schedule of Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity method investments	$ 461		$ 440
Measurement alternative method investments	8		7
Total investments in unconsolidated entities	469		$ 447
Equity method investments, combined income statements
Revenues	1,657	$ 1,689
Operating expenses	1,162	1,215
Operating income	495	474
Other income (expense), net	3	(5)
Net income	$ 498	$ 469