Goodwill and Intangible Assets Schedule of Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 13,751		$ 13,751		$ 13,038
Finite-Lived Intangible Assets, Accumulated Amortization	(3,897)		(3,897)		(3,509)
Intangible Assets, Net (Excluding Goodwill)	9,854		9,854		9,529
Amortization of Intangible Assets	126	124	391	370
Customer Contracts Relationships and Covenants Not to Compete [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	6,465		6,465		5,840
Finite-Lived Intangible Assets, Accumulated Amortization	(3,434)		(3,434)		(3,083)
Intangible Assets, Net (Excluding Goodwill)	3,031		3,031		2,757
Favorable Leases and Other [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	888		888		800
Finite-Lived Intangible Assets, Accumulated Amortization	(463)		(463)		(426)
Intangible Assets, Net (Excluding Goodwill)	425		425		374
Trademarks [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	6,398		6,398		6,398
Finite-Lived Intangible Assets, Accumulated Amortization	0		0		0
Intangible Assets, Net (Excluding Goodwill)	$ 6,398		$ 6,398		$ 6,398