Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Summary Of Significant Accounting Policies [Abstract]

Schedule Of Revenues From External Customers

	For the three months ended				For the nine months ended
	September 30,				September 30,
($ in millions)	2017		2016		2017		2016
Data and Internet services	$	956	$	1,045	$	2,923	$	2,680
Voice services		702		809		2,177		2,112
Video services		318		392		994		879
Other		84		73		231		218
Customer revenue		2,060		2,319		6,325		5,889
Switched access and subsidy		191		205		586		598
Total revenue	$	2,251	$	2,524	$	6,911	$	6,487