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



	Three Months Ended September 30, 2017
	West			Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	553		$	1,127	$	906		$	—		$	2,586
Intersegment revenues	2			4		2			(8		)	—
Total operating revenues	$	555		$	1,131	$	908		$	(8	)	$	2,586
Commodity Margin	$	327		$	201	$	336		$	—		$	864
Add: Mark-to-market commodity activity, net and other⁽¹⁾	(40		)	88		(39		)	(8		)	1
Less:
Plant operating expense	83			77		75			(7		)	228
Depreciation and amortization expense	63			61		55			—			179
Sales, general and other administrative expense	10			16		10			1			37
Other operating expenses	13			6		6			(2		)	23
Impairment losses	—			12		—			—			12
(Income) from unconsolidated subsidiaries	—			—		(7		)	—			(7		)
Income from operations	118			117		158			—			393
Interest expense												156
Debt extinguishment costs and other (income) expense, net												8
Income before income taxes												$	229



	Three Months Ended September 30, 2016
	West		Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	524	$	1,067	$	764		$	—		$	2,355
Intersegment revenues	1		3		2			(6		)	—
Total operating revenues	$	525	$	1,070	$	766		$	(6	)	$	2,355
Commodity Margin	$	298	$	198	$	324		$	—		$	820
Add: Mark-to-market commodity activity, net and other⁽¹⁾	11		110		(51		)	(7		)	63
Less:
Plant operating expense	79		65		78			(7		)	215
Depreciation and amortization expense	56		53		52			—			161
Sales, general and other administrative expense	9		13		12			(1		)	33
Other operating expenses	8		2		7			1			18
(Income) from unconsolidated subsidiaries	—		—		(6		)	—			(6		)
Income from operations	157		175		130			—			462
Interest expense											158
Other (income) expense, net											7
Income before income taxes											$	297



	Nine Months Ended September 30, 2017
	West			Texas			East			Consolidation and Elimination			Total
Revenues from external customers	$	1,666		$	2,723		$	2,562		$	—		$	6,951
Intersegment revenues	4			12			6			(22		)	—
Total operating revenues	$	1,670		$	2,735		$	2,568		$	(22	)	$	6,951
Commodity Margin	$	792		$	516		$	761		$	—		$	2,069
Add: Mark-to-market commodity activity, net and other⁽²⁾	(1		)	28			(65		)	(22		)	(60		)
Less:
Plant operating expense	291			282			260			(21		)	812
Depreciation and amortization expense	189			187			166			—			542
Sales, general and other administrative expense	31			54			31			1			117
Other operating expenses	30			12			23			(2		)	63
Impairment losses	28			13			—			—			41
(Gain) on sale of assets, net	—			—			(27		)	—			(27		)
(Income) from unconsolidated subsidiaries	—			—			(17		)	—			(17		)
Income (loss) from operations	222			(4		)	260			—			478
Interest expense													469
Debt extinguishment costs and other (income) expense, net													42
Loss before income taxes													$	(33	)



	Nine Months Ended September 30, 2016
	West			Texas		East			Consolidation and Elimination			Total
Revenues from external customers	$	1,159		$	2,129	$	1,846		$	—		$	5,134
Intersegment revenues	4			10		9			(23		)	—
Total operating revenues	$	1,163		$	2,139	$	1,855		$	(23	)	$	5,134
Commodity Margin	$	749		$	511	$	797		$	—		$	2,057
Add: Mark-to-market commodity activity, net and other⁽²⁾	(5		)	7		(44		)	(21		)	(63		)
Less:
Plant operating expense	268			236		258			(21		)	741
Depreciation and amortization expense	168			159		163			—			490
Sales, general and other administrative expense	27			43		36			—			106
Other operating expenses	23			6		27			(1		)	55
Impairment losses	13			—		—			—			13
(Income) from unconsolidated subsidiaries	—			—		(16		)	—			(16		)
Income from operations	245			74		285			1			605
Interest expense												472
Debt extinguishment costs and other (income) expense, net												33
Income before income taxes												$	100

_________


(1)	Includes $33 million and $40 million of lease levelization and $39 million and $25 million of amortization expense for the three months ended September 30, 2017 and 2016, respectively.


(2)	Includes $(13) million and $(2) million of lease levelization and $143 million and $79 million of amortization expense for the nine months ended September 30, 2017 and 2016, respectively.