Supplemental Information on Oil and Gas Producing Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Supplemental Information on Oil and Gas Producing Activities (Unaudited)

Schedule of capitalized costs relating to oil and gas producing activities

	Year ended December 31
	2011			2012
	(In thousands)
Proved properties	$	2,497,306			1,689,132
Unproved properties		834,255			1,243,237
		3,331,561			2,932,369
Accumulated depreciation and depletion		(586,444	)		(158,210	)
Net capitalized costs	$	2,745,117			2,774,159

Schedule of costs incurred in certain oil and gas activities

	Year ended December 31
	2010		2011		2012
	(In thousands)
Acquisition costs
Proved property	$	50,657	$	105,405	$	10,254
Unproved property		247,733		195,131		687,403
Development costs		224,297		433,053		690,517
Exploration costs		75,961		95,563		158,074
Total costs incurred	$	598,648	$	829,152	$	1,546,248

Schedule of results of operations (including discontinued operations) for oil and gas producing activities

	Year ended December 31
	2010			2011			2012
	(In thousands)
Revenues	$	206,462			391,994			390,378
Operating expenses:
Production expenses		80,097			136,635			185,505
Exploration expenses		24,794			9,876			15,339
Depreciation and depletion		124,341			164,011			181,664
Impairment		35,859			11,051			13,032
Results of operations before income tax expense (benefit)		(58,629	)		70,421			(5,162	)
Income tax (expense) benefit		6,449			(26,056	)		2,008
Results of operations	$	(52,180	)		44,365			(3,154	)

Schedule of proved developed and undeveloped reserves

	Natural gas (Bcf)			NGLS (MMBbl)		Oil and condensate (MMBbl)			Equivalents (Bcfe)
Proved developed and undeveloped reserves:
December 31, 2009		1,130			—		1			1,141
Revisions		38			35		1			253
Extensions, discoveries and other additions		1,248			69		8			1,712
Production		(45	)		—		—	(a)		(47	)
Purchase of reserves		172			—		—			172
December 31, 2010		2,543			104		10			3,231

(a)

Less than 1.0

	Natural gas (Bcf)			NGLS (MMBbl)			Oil and condensate (MMBbl)			Equivalents (Bcfe)
Revisions		(223	)		2			7			(172	)
Extensions, discoveries and other additions		1,644			57			—	(a)		1,982
Production		(84	)		(1	)		—	(a)		(89	)
Purchase of reserves		52			2			—			66
Sale of reserves in place		(1	)		—			—			(1	)
December 31, 2011		3,931			164			17			5,017
Revisions		198			4			—	(a)		222
Extensions, discoveries and other additions		1,242			115			3			1,951
Production		(87	)		—	(a)		—	(a)		(87	)
Sale of reserves in place		(1,590	)		(80	)		(17	)		(2,174	)
December 31, 2012		3,694			203			3			4,929

Schedule of proved developed and undeveloped reserves by fiscal year maturity

	Natural gas (Bcf)		NGLS (MMBbl)		Oil and condensate (MMBbl)		Equivalents (Bcfe)
Proved developed reserves:
December 31, 2010		400		9		1		457
December 31, 2011		718		19		2		844
December 31, 2012		828		36		1		1,047
Proved undeveloped reserves:
December 31, 2010		2,143		95		10		2,774
December 31, 2011		3,213		145		15		4,173
December 31, 2012		2,866		167		2		3,882

Schedule of standardized measure of discounted future net cash flows attributable to proved reserves

	Year ended December 31
	2010			2011			2012
	(In millions)
Future cash inflows	$	13,114			20,046			12,151
Future production costs		(3,088	)		(3,491	)		(1,660	)
Future development costs		(4,036	)		(5,085	)		(3,270	)
Future net cash flows before income tax		5,990			11,470			7,221
Future income tax expense		(1,438	)		(3,287	)		(1,603	)
Future net cash flows		4,552			8,183			5,618
10% annual discount for estimated timing of cash flows		(3,455	)		(5,713	)		(4,017	)
Standardized measure of discounted future net cash flows	$	1,097			2,470			1,601

Schedule of weighted average prices used to estimate the Company's total equivalent reserves

	Arkoma		Piceance		Appalachia
	(Per Mcfe)
December 31, 2010	$	4.18		3.93		4.51
December 31, 2011		3.90		3.84		4.16
December 31, 2012		NA		NA		2.78

Schedule of changes in standardized measure of discounted future net cash flow

	Year ended December 31
	2010			2011			2012
	(In millions)
Sales of oil and gas, net of productions costs	$	(126	)		(255	)		(147	)
Net changes in prices and production costs		382			215			(1,631	)
Development costs incurred during the period		81			247			296
Net changes in future development costs		(61	)		(106	)		(92	)
Extensions, discoveries and other additions		695			1,684			813
Acquisitions		92			51			—
Divestitures		—			—			(1,277	)
Revisions of previous quantity estimates		113			(182	)		88
Accretion of discount		29			147			322
Net change in income taxes		(359	)		(605	)		653
Other changes		16			177			106
Net increase (decrease)		862			1,373			(869	)
Beginning of year		235			1,097			2,470
End of year	$	1,097			2,470			1,601