Segment Information

6 Months Ended

Jun. 30, 2016

Segment Reporting [Abstract]

Segment Information

Segment Information

We assess our business on a regional basis due to the impact on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors impacting supply and demand. At June 30, 2016, our reportable segments were West (including geothermal), Texas and East (including Canada). 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 reviewed by our chief operating decision maker to assess the performance of our segments. The tables below show our financial data for our segments for the periods indicated (in millions).

	Three Months Ended June 30, 2016
	West			Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	211		$	530	$	423		$	—		$	1,164
Intersegment revenues	1			4		4			(9		)	—
Total operating revenues	$	212		$	534	$	427		$	(9	)	$	1,164
Commodity Margin	$	254		$	160	$	243		$	—		$	657
Add: Mark-to-market commodity activity, net and other(1)	(62		)	7		28			(8		)	(35		)
Less:
Plant operating expense	98			85		96			(8		)	271
Depreciation and amortization expense	56			53		53			—			162
Sales, general and other administrative expense	8			14		12			1			35
Other operating expenses	7			2		10			(2		)	17
(Income) from unconsolidated investments in power plants	—			—		(3		)	—			(3		)
Income from operations	23			13		103			1			140
Interest expense, net of interest income												156
Debt extinguishment costs and other (income) expense, net												22
Loss before income taxes												$	(38	)

	Three Months Ended June 30, 2015
	West			Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	421		$	570	$	451		$	—		$	1,442
Intersegment revenues	—			5		2			(7		)	—
Total operating revenues	$	421		$	575	$	453		$	(7	)	$	1,442
Commodity Margin	$	240		$	170	$	247		$	—		$	657
Add: Mark-to-market commodity activity, net and other(1)	(14		)	10		30			(7		)	19
Less:
Plant operating expense	120			82		77			(7		)	272
Depreciation and amortization expense	65			50		45			—			160
Sales, general and other administrative expense	6			15		9			—			30
Other operating expenses	10			2		8			—			20
(Income) from unconsolidated investments in power plants	—			—		(7		)	—			(7		)
Income from operations	25			31		145			—			201
Interest expense, net of interest income												157
Debt modification costs and other (income) expense, net												18
Income before income taxes												$	26

	Six Months Ended June 30, 2016
	West			Texas			East			Consolidation and Elimination			Total
Revenues from external customers	$	635		$	1,062		$	1,082		$	—		$	2,779
Intersegment revenues	3			7			7			(17		)	—
Total operating revenues	$	638		$	1,069		$	1,089		$	(17	)	$	2,779
Commodity Margin	$	451		$	313		$	473		$	—		$	1,237
Add: Mark-to-market commodity activity, net and other(2)	(16		)	(103		)	7			(14		)	(126		)
Less:
Plant operating expense	189			171			180			(14		)	526
Depreciation and amortization expense	125			106			111			—			342
Sales, general and other administrative expense	18			30			24			1			73
Other operating expenses	15			4			20			(2		)	37
(Income) from unconsolidated investments in power plants	—			—			(10		)	—			(10		)
Income (loss) from operations	88			(101		)	155			1			143
Interest expense, net of interest income													312
Debt extinguishment costs and other (income) expense, net													28
Loss before income taxes													$	(197	)

	Six Months Ended June 30, 2015
	West		Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	936	$	1,151	$	1,001		$	—		$	3,088
Intersegment revenues	2		8		4			(14		)	—
Total operating revenues	$	938	$	1,159	$	1,005		$	(14	)	$	3,088
Commodity Margin	$	458	$	319	$	415		$	—		$	1,192
Add: Mark-to-market commodity activity, net and other(2)	105		51		(22		)	(14		)	120
Less:
Plant operating expense	226		171		149			(14		)	532
Depreciation and amortization expense	132		99		87			—			318
Sales, general and other administrative expense	16		32		19			—			67
Other operating expenses	20		4		16			—			40
(Income) from unconsolidated investments in power plants	—		—		(12		)	—			(12		)
Income from operations	169		64		134			—			367
Interest expense, net of interest income											310
Debt modification and extinguishment costs and other (income) expense, net											39
Income before income taxes											$	18

_________

(1) Includes $(20) million and $(18) million of lease levelization and $27 million and $3 million of amortization expense for the three months ended June 30, 2016 and 2015, respectively.

(2) Includes $(42) million and $(42) million of lease levelization and $54 million and $7 million of amortization expense for the six months ended June 30, 2016 and 2015, respectively.