The tables below show our financial data for our segments for the periods indicated (in millions).



	Year Ended December 31, 2015
	West		Texas			East			Consolidation and Elimination			Total
Revenues from external customers	$	2,089	$	2,344		$	2,039		$	—		$	6,472
Intersegment revenues	5		15			8			(28		)	—
Total operating revenues	$	2,094	$	2,359		$	2,047		$	(28	)	$	6,472
Commodity Margin	$	1,106	$	736		$	944		$	—		$	2,786
Add: Mark-to-market commodity activity, net and other⁽¹⁾	160		(120		)	(92		)	(29		)	(81		)
Less:
Plant operating expense	416		338			292			(28		)	1,018
Depreciation and amortization expense	250		204			184			—			638
Sales, general and other administrative expense	35		63			40			—			138
Other operating expenses	37		9			36			(2		)	80
(Income) from unconsolidated investments in power plants	—		—			(24		)	—			(24		)
Income from operations	528		2			324			1			855
Interest expense, net of interest income												624
Debt modification and extinguishment costs and other (income) expense, net												58
Income before income taxes												$	173



	Year Ended December 31, 2014
	West		Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	2,352	$	3,229	$	2,449		$	—		$	8,030
Intersegment revenues	6		23		47			(76		)	—
Total operating revenues	$	2,358	$	3,252	$	2,496		$	(76	)	$	8,030
Commodity Margin⁽²⁾	$	1,050	$	760	$	949		$	—		$	2,759
Add: Mark-to-market commodity activity, net and other⁽¹⁾	220		142		48			(31		)	379
Less:
Plant operating expense	385		313		302			(31		)	969
Depreciation and amortization expense	245		191		168			(1		)	603
Sales, general and other administrative expense	41		64		39			—			144
Other operating expenses	50		5		32			1			88
Impairment losses	—		—		123			—			123
(Gain) on sale of assets, net	—		—		(753		)	—			(753		)
(Income) from unconsolidated investments in power plants	—		—		(25		)	—			(25		)
Income from operations	549		329		1,111			—			1,989
Interest expense, net of interest income											639
Debt extinguishment costs and other (income) expense, net											367
Income before income taxes											$	983



	Year Ended December 31, 2013
	West			Texas			East			Consolidation and Elimination			Total
Revenues from external customers	$	1,937		$	2,347		$	2,017		$	—		$	6,301
Intersegment revenues	5			(4		)	117			(118		)	—
Total operating revenues	$	1,942		$	2,343		$	2,134		$	(118	)	$	6,301
Commodity Margin⁽²⁾	$	1,020		$	632		$	916		$	—		$	2,568
Add: Mark-to-market commodity activity, net and other⁽¹⁾	(50		)	51			27			(31		)	(3		)
Less:
Plant operating expense	365			269			292			(31		)	895
Depreciation and amortization expense	227			165			203			(2		)	593
Sales, general and other administrative expense	37			56			42			1			136
Other operating expenses	45			3			33			—			81
Impairment losses	16			—			—			—			16
(Income) from unconsolidated investments in power plants	—			—			(30		)	—			(30		)
Income from operations	280			190			403			1			874
Interest expense, net of interest income													690
Debt extinguishment costs and other (income) expense, net													164
Income before income taxes													$	20

__________


(1)	Includes $(2) million, $(5) million and $6 million of lease levelization and $20 million, $14 million and $14 million of amortization expense for the years ended December 31, 2015, 2014 and 2013, respectively.


(2)	Our East segment includes Commodity Margin of $81 million and $152 million for the years ended December 31, 2014 and 2013, respectively, related to the six power plants in our East segment that were sold in July 2014.