Goodwill and Other Intangible Assets (Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Net Amount	$ 1,218
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	45 months	40 months
Gross Carrying Amount	69	54
Accumulated Amortization	24	18
Net Amount	45	36
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	12 years	13 years
Gross Carrying Amount	1,508	1,227
Accumulated Amortization	366	285
Net Amount	1,142	942
Trade names and associated trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	34 months	40 months
Gross Carrying Amount	81	81
Accumulated Amortization	50	41
Net Amount	$ 31	$ 40