Segment Information (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The following tables provide information on a reportable segment basis for the years ended December 31 (in millions):

	Years Ended December 31,
	2014		2013		2012
Operating revenue:
Regulated electric	$	779	$	747	$	726
Regulated gas	125		106		108
Total operating revenue	$	904	$	853	$	834
Cost of sales:
Regulated electric	$	361	$	292	$	263
Regulated gas	76		56		62
Total cost of sales	$	437	$	348	$	325
Gross margin:
Regulated electric	$	418	$	455	$	463
Regulated gas	49		50		46
Total gross margin	$	467	$	505	$	509
Operating and maintenance:
Regulated electric	$	140	$	176	$	169
Regulated gas	18		21		21
Total operating and maintenance	$	158	$	197	$	190
Depreciation and amortization:
Regulated electric	$	90	$	106	$	95
Regulated gas	15		17		13
Total depreciation and amortization	$	105	$	123	$	108
Operating income:
Regulated electric	$	165	$	134	$	179
Regulated gas	13		6		9
Total operating income	$	178	$	140	$	188
Interest expense, net of allowance for borrowed funds:
Regulated electric	$	55	$	55	$	57
Regulated gas	4		5		6
Total interest expense, net of allowance for borrowed funds	$	59	$	60	$	63
Income tax (benefit) expenses:
Regulated electric	$	43	$	32	$	40
Regulated gas	4		1		—
Total income tax (benefit) expense	$	47	$	33	$	40

	Years Ended December 31,
	2014		2013		2012
Capital expenditures:
Regulated electric	$	177	$	141	$	191
Regulated gas	19		16		20
Total capital expenditures	$	196	$	157	$	211
	As of December 31,
Total assets:	2014		2013		2012
Regulated electric	$	3,031	$	2,957	$	2,919
Regulated gas	327		335		319
Regulated common assets(1)	30		77		78
Total assets	$	3,388	$	3,369	$	3,316

(1) Consists principally of cash and cash equivalents not included in either the regulated electric or regulated natural gas segments.