Segment Information

We assess our business on a regional basis due to the effect on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors affecting supply and demand. At June 30, 2019, our geographic reportable segments for our wholesale business are West (including geothermal), Texas and East (including Canada) and we have a separate reportable segment for our retail business. We continue to evaluate the optimal manner in which we assess our performance including our segments and future changes may result in changes to the composition of our geographic segments.

Commodity Margin is a key operational measure of profit reviewed by our chief operating decision maker to assess the performance of our segments. The tables below show financial data for our segments (including a reconciliation of our Commodity Margin to income (loss) from operations by segment) for the periods indicated (in millions):



	Three Months Ended June 30, 2019
	Wholesale										Consolidation
	West		Texas		East			Retail			Elimination			Total
Total operating revenues⁽¹⁾	$	649	$	899	$	646		$	1,082		$	(677	)	$	2,599

Commodity Margin	$	251	$	173	$	235		$	93		$	—		$	752
Add: Mark-to-market commodity activity, net and other⁽²⁾	58		240		94			(182		)	(10		)	200
Less:
Operating and maintenance expense	84		66		72			33			(10		)	245
Depreciation and amortization expense	60		54		48			13			—			175
General and other administrative expense	5		15		10			4			—			34
Other operating expenses	7		1		11			—			—			19
Impairment losses	—		—		40			—			—			40
(Income) from unconsolidated subsidiaries	—		—		(6		)	1			—			(5		)
Income (loss) from operations	153		277		154			(140		)	—			444
Interest expense														157
Gain on extinguishment of debt and other (income) expense, net														8
Income before income taxes														$	279



	Three Months Ended June 30, 2018
	Wholesale											Consolidation
	West			Texas		East			Retail			Elimination			Total
Total operating revenues⁽¹⁾	$	355		$	993	$	341		$	935		$	(365	)	$	2,259

Commodity Margin	$	241		$	151	$	225		$	77		$	—		$	694
Add: Mark-to-market commodity activity, net and other⁽²⁾	(23		)	301		(7		)	(67		)	(8		)	196
Less:
Operating and maintenance expense	80			65		65			41			(9		)	242
Depreciation and amortization expense	67			57		49			13			—			186
General and other administrative expense	5			13		8			5			—			31
Other operating expenses	8			3		8			—			—			19
(Income) from unconsolidated subsidiaries	—			—		(6		)	1			—			(5		)
Income (loss) from operations	58			314		94			(50		)	1			417
Interest expense															157
Other (income) expense, net															62
Income before income taxes															$	198



	Six Months Ended June 30, 2019
	Wholesale										Consolidation
	West		Texas		East			Retail			Elimination			Total
Total operating revenues⁽³⁾	$	1,331	$	1,642	$	1,335		$	2,080		$	(1,190	)	$	5,198

Commodity Margin	$	515	$	335	$	500		$	181		$	—		$	1,531
Add: Mark-to-market commodity activity, net and other⁽⁴⁾	114		284		107			(235		)	(18		)	252
Less:
Operating and maintenance expense	165		131		139			67			(18		)	484
Depreciation and amortization expense	133		99		91			26			—			349
General and other administrative expense	12		27		19			8			—			66
Other operating expenses	16		3		19			—			—			38
Impairment losses	—		—		55			—			—			55
(Income) from unconsolidated subsidiaries	—		—		(12		)	1			—			(11		)
Income (loss) from operations	303		359		296			(156		)	—			802
Interest expense														306
Gain on extinguishment of debt and other (income) expense, net														27
Income before income taxes														$	469



	Six Months Ended June 30, 2018
	Wholesale											Consolidation
	West			Texas			East			Retail		Elimination			Total
Total operating revenues⁽³⁾	$	835		$	1,133		$	955		$	1,873	$	(528	)	$	4,268

Commodity Margin	$	426		$	317		$	409		$	154	$	—		$	1,306
Add: Mark-to-market commodity activity, net and other⁽⁴⁾	(10		)	(246		)	33			61		(15		)	(177		)
Less:
Operating and maintenance expense	170			145			136			81		(15		)	517
Depreciation and amortization expense	134			133			94			26		—			387
General and other administrative expense	21			38			23			9		—			91
Other operating expenses	22			19			15			—		—			56
(Income) from unconsolidated subsidiaries	—			—			(12		)	1		—			(11		)
Income (loss) from operations	69			(264		)	186			98		—			89
Interest expense															308
Other (income) expense, net															69
Loss before income taxes															$	(288	)

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(1)	Includes intersegment revenues of $100 million and $70 million in the West, $348 million and $276 million in Texas, $228 million and $18 million in the East and $1 million and $1 million in Retail for the three months ended June 30, 2019 and 2018, respectively.


(2)	Includes $(19) million and $(19) million of lease levelization and $18 million and $25 million of amortization expense for the three months ended June 30, 2019 and 2018, respectively.


(3)	Includes intersegment revenues of $262 million and $184 million in the West, $559 million and $209 million in Texas, $365 million and $133 million in the East and $4 million and $2 million in Retail for the six months ended June 30, 2019 and 2018, respectively.


(4)	Includes $(35) million and $(35) million of lease levelization and $39 million and $53 million of amortization expense for the six months ended June 30, 2019 and 2018, respectively.