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 September 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 September 30, 2019
	Wholesale										Consolidation
	West		Texas			East			Retail		Elimination			Total
Total operating revenues⁽¹⁾	$	856	$	867		$	348		$	1,096	$	(375	)	$	2,792

Commodity Margin	$	393	$	369		$	265		$	100	$	—		$	1,127
Add: Mark-to-market commodity activity, net and other⁽²⁾	110		(107		)	(69		)	108		(8		)	34
Less:
Operating and maintenance expense	82		71			69			41		(8		)	255
Depreciation and amortization expense	61		47			51			14		—			173
General and other administrative expense	10		13			12			4		—			39
Other operating expenses	9		2			4			—		—			15
(Income) from unconsolidated subsidiaries	—		—			(3		)	—		—			(3		)
Income from operations	341		129			63			149		—			682
Interest expense														153
Loss on extinguishment of debt and other (income) expense, net														17
Income before income taxes														$	512



	Three Months Ended September 30, 2018
	Wholesale											Consolidation
	West			Texas		East			Retail			Elimination			Total
Total operating revenues⁽¹⁾	$	701		$	1,022	$	460		$	1,125		$	(418	)	$	2,890

Commodity Margin	$	356		$	187	$	320		$	111		$	—		$	974
Add: Mark-to-market commodity activity, net and other⁽²⁾	(13		)	137		(26		)	(20		)	(8		)	70
Less:
Operating and maintenance expense	85			63		72			36			(8		)	248
Depreciation and amortization expense	70			57		39			13			—			179
General and other administrative expense	7			12		7			5			—			31
Other operating expenses	11			3		9			—			—			23
(Income) from unconsolidated subsidiaries	—			—		(5		)	—			—			(5		)
Income from operations	170			189		172			37			—			568
Interest expense															158
Loss on extinguishment of debt and other (income) expense, net															4
Income before income taxes															$	406



	Nine Months Ended September 30, 2019
	Wholesale										Consolidation
	West		Texas		East			Retail			Elimination			Total
Total operating revenues⁽³⁾	$	2,187	$	2,509	$	1,683		$	3,176		$	(1,565	)	$	7,990

Commodity Margin	$	908	$	704	$	765		$	281		$	—		$	2,658
Add: Mark-to-market commodity activity, net and other⁽⁴⁾	224		177		38			(127		)	(26		)	286
Less:
Operating and maintenance expense	247		202		208			108			(26		)	739
Depreciation and amortization expense	194		146		142			40			—			522
General and other administrative expense	22		40		31			12			—			105
Other operating expenses	25		5		23			—			—			53
Impairment losses	—		—		55			—			—			55
(Income) from unconsolidated subsidiaries	—		—		(15		)	1			—			(14		)
Income (loss) from operations	644		488		359			(7		)	—			1,484
Interest expense														459
Loss on extinguishment of debt and other (income) expense, net														44
Income before income taxes														$	981



	Nine Months Ended September 30, 2018
	Wholesale											Consolidation
	West			Texas			East			Retail		Elimination			Total
Total operating revenues⁽³⁾	$	1,536		$	2,155		$	1,415		$	2,998	$	(946	)	$	7,158

Commodity Margin	$	782		$	504		$	729		$	265	$	—		$	2,280
Add: Mark-to-market commodity activity, net and other⁽⁴⁾	(23		)	(109		)	7			41		(23		)	(107		)
Less:
Operating and maintenance expense	255			208			208			117		(23		)	765
Depreciation and amortization expense	204			190			133			39		—			566
General and other administrative expense	28			50			30			14		—			122
Other operating expenses	33			22			24			—		—			79
(Income) from unconsolidated subsidiaries	—			—			(17		)	1		—			(16		)
Income (loss) from operations	239			(75		)	358			135		—			657
Interest expense															466
Loss on extinguishment of debt and other (income) expense, net															73
Income before income taxes															$	118

_________


(1)	Includes intersegment revenues of $133 million and $160 million in the West, $225 million and $238 million in Texas, $13 million and $19 million in the East and $4 million and $1 million in Retail for the three months ended September 30, 2019 and 2018, respectively.


(2)	Includes $31 million and $30 million of lease levelization and $20 million and $26 million of amortization expense for the three months ended September 30, 2019 and 2018, respectively.


(3)	Includes intersegment revenues of $395 million and $344 million in the West, $784 million and $447 million in Texas, $378 million and $152 million in the East and $8 million and $3 million in Retail for the nine months ended September 30, 2019 and 2018, respectively.


(4)	Includes $(4) million and $(5) million of lease levelization and $59 million and $79 million of amortization expense for the nine months ended September 30, 2019 and 2018, respectively.