Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets (excluding goodwill)	$ 6,398	$ 6,398
Intangible assets, gross	18,870	18,587
Intangible assets, accumulated amortization	(5,303)	(4,709)
Intangible assets, net	13,567	13,878
Customer Contracts Relationships and Covenants Not to Compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	11,340	10,594
Intangible assets, accumulated amortization	(4,624)	(4,092)
Intangible assets, net	6,716	6,502
Favorable Leases and Other
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	1,132	1,595
Intangible assets, accumulated amortization	(679)	(617)
Intangible assets, net	$ 453	$ 978