Segment Information (Notes)

3 Months Ended

Mar. 31, 2014

Segment Reporting [Abstract]

Segment Information

Segment Information

The Company has identified two reportable operating segments: electric and natural gas. The electric segment derives most of its revenue from retail sales of electricity to residential, commercial, and industrial customers and from wholesale sales. The natural gas segment derives most of its revenue from retail sales of natural gas to residential, commercial, and industrial customers and also obtains revenue by transporting natural gas owned by others through its distribution system. Pricing for electric and natural gas sales are established separately by the PUCN; therefore, management also reviews each segment separately to make decisions regarding allocation of resources and in evaluating performance.

Operating revenue, cost of fuel, energy and capacity and natural gas purchased for resale are key drivers of the Company's results of operations as they encompass retail and wholesale electricity and natural gas revenue and the direct costs associated with providing electricity and natural gas to customers. The Company believes that a discussion of gross margin, representing operating revenue less cost of fuel, energy and capacity and natural gas purchased for resale, is therefore meaningful.

The following tables provide information on a reportable segment basis for the three-month periods endedMarch 31 (in millions):

	2014
			Natural
	Electric		Gas		Total
Operating revenue	$	177	$	44	$	221
Cost of fuel, energy and capacity	80		—		80
Natural gas purchased for resale	—		29		29
Gross margin	$	97	$	15	112
Operating and maintenance expense					34
Depreciation and amortization					26
Property and other taxes					6
Interest expense, net of allowance for debt funds					15
Allowance for equity funds					(1		)
Other, net					(2		)
Income before income tax expense					$	34

	2013
			Natural
	Electric		Gas		Total
Operating revenue	$	172	$	34	$	206
Cost of fuel, energy and capacity	62		—		62
Natural gas purchased for resale	—		18		18
Gross margin(1)	$	110	$	16	126
Operating and maintenance expenses					48
Depreciation and amortization					25
Property and other taxes					6
Interest expense, net of allowance for debt funds					16
Allowance for equity funds					(1		)
Other, net					(2		)
Income before income tax expense					$	34

(1) Energy efficiency program costs were reclassified from gross margin to operating and maintenance expenses for presentation purposes.

	As of
	March 31,		December 31,
	2014		2013
Total assets:
Electric	$	2,952	$	2,957
Natural gas	347		335
Other(1)	89		77
Total assets	$	3,388	$	3,369

(1) Consists principally of cash and cash equivalents.