Investment 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	$ 487		$ 467
Measurement alternative method investments	22		21
Total investments in unconsolidated entities	509	$ 507	$ 488
Equity method investments, combined income statements
Revenues	1,662	1,696
Operating expenses	1,166	1,221
Operating income	496	475
Other income (expense), net	3	(6)
Net income	$ 499	$ 469