Investments in Unconsolidated Entities - Schedule of Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity method investments	$ 460		$ 460		$ 440
Measurement alternative method investments	7		7		7
Total investments in unconsolidated entities	467		467		$ 447
Schedule of Equity Method Investments [Line Items]
Revenues	1,027	$ 1,031	2,964	$ 2,970
Operating expenses	962	1,011	2,796	2,855
Operating income	65	20	168	115
Net income	85	24	227	115
Equity method investments
Schedule of Equity Method Investments [Line Items]
Revenues	1,634	1,714	4,871	5,058
Operating expenses	1,136	1,241	3,392	3,644
Operating income	498	473	1,479	1,414
Other income (expense), net	(4)	(1)	(1)	(3)
Net income	$ 494	$ 472	$ 1,478	$ 1,411