Investments in Unconsolidated Entities - Schedule of Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity method investments	$ 437		$ 437		$ 440
Measurement alternative method investments	8		8		7
Total investments in unconsolidated entities	445		445		$ 447
Schedule of Equity Method Investments [Line Items]
Revenues	973	$ 973	1,937	$ 1,939
Operating expenses	920	943	1,833	1,844
Operating income	53	30	104	95
Other income (expense), net	0	0	0	(1)
Net income	69	32	141	90
Equity method investments
Schedule of Equity Method Investments [Line Items]
Revenues	1,580	1,654	3,237	3,343
Operating expenses	1,093	1,187	2,256	2,402
Operating income	487	467	981	941
Other income (expense), net	(2)	4	2	(2)
Net income	$ 485	$ 471	$ 983	$ 939