Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2018

Accounts Receivable [Abstract]

Accounts Receivable

($ in millions)	2018		2017
Retail and Wholesale	$	745	$	801
Other		83		87
Less: Allowance for doubtful accounts		(105)		(69)
Accounts receivable, net	$	723	$	819

Schedule Of Allowance For Doubtful Accounts

							Charged
							(Credited) to
							Switched and
	Balance at		ASC 606		Charged to		Nonswitched				Balance at
	beginning of		Transition		Other		Revenue and		Write-offs, net		end of
($ in millions)	the Period		Adjustment		Revenue		Other		of Recoveries		the Period
2016	$	57	$	-	$	164	$	15	$	(105)	$	131
2017	$	131	$	-	$	109	$	(22)	$	(149)	$	69
2018	$	69	$	32	$	79	$	14	$	(89)	$	105