Basis of Presentation and Summary of Significant Accounting Policies (Details 4) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	15 years
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	7 years
Integrated billing and customer care system
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	20 years
Finite-lived intangible assets, gross	$ 237
Other
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	4 years