Natural Gas and Oil Producing Acitivities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Natural Gas And Oil Properties [Abstract]

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure

	2012				2011
	(in thousands)
Proved properties	$	10,259,226		$		8,601,818
Unproved properties		1,023,888	(1)			942,890	(1)
Total capitalized costs		11,283,114				9,544,708
Less:  Accumulated depreciation, depletion and amortization		6,774,174				4,092,410
Net capitalized costs	$	4,508,940		$		5,452,298

Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization

	2012		2011		2010		Prior		Total
	(in thousands)
Property acquisition costs	$	193,258	$	232,615	$	123,736	$	45,081	$	594,690	(1)
Exploration and development costs		233,888		65,479		15,357		36,958		351,682	(1)
Capitalized interest		11,578		25,163		18,989		21,786		77,516	(1)
	$	438,724	$	323,257	$	158,082	$	103,825	$	1,023,888

Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure

	2012			2011			2010
	(in thousands, except per Mcfe amounts)
Proved property acquisition costs	$	–		$	17		$	–
Unproved property acquisition costs		220,822	(1)		262,886	(1)		229,909	(1)
Exploration costs		197,280	(2)		63,419	(2)		27,062	(2)
Development costs		1,492,841			1,633,784			1,524,453
Capitalized costs incurred		1,910,943			1,960,106			1,781,424
Full cost pool amortization per Mcfe	$	1.31		$	1.30		$	1.34

Results of Operations for Oil and Gas Producing Activities Disclosure

	2012		2011		2010
	(in thousands)
Sales	$	1,948,222	$	2,100,488	$	1,890,444
Production (lifting) costs		(505,271)		(469,153)		(376,939)
Depreciation, depletion and amortization		(765,192)		(666,107)		(561,003)
Impairment of natural gas and oil properties		(1,939,734)		–		–
		(1,261,975)		965,228		952,502
Provision (benefit) for income taxes		(502,690)		376,049		371,281
Results of operations	$	(759,285)	$	589,179	$	581,221

Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities

	2012		2011		2010
	Natural		Natural		Natural
	Gas	Oil	Gas	Oil	Gas	Oil
	(MMcf)	(MBbls)	(MMcf)	(MBbls)	(MMcf)	(MBbls)
Proved reserves, beginning of year	5,887,207	996	4,929,980	1,219	3,650,303	1,059
Revisions of previous estimates	(2,087,985)	(44)	34,505	(125)	309,292	50
Extensions, discoveries and other additions	918,594	154	1,459,428	2	1,429,439	281
Production	(564,484)	(83)	(499,433)	(97)	(403,636)	(171)
Acquisition of reserves in place	–	–	13	–	–	–
Disposition of reserves in place	(136,534)	(779)	(37,286)	(3)	(55,418)	–
Proved reserves, end of year	4,016,798	244	5,887,207	996	4,929,980	1,219
Proved developed reserves:
Beginning of year	3,254,018	983	2,687,238	1,173	1,972,767	1,028
End of year	3,195,662	243	3,254,018	983	2,687,238	1,173
Proved undeveloped reserves:
Beginning of year	2,633,189	13	2,242,742	46	1,677,536	31
End of year	821,136	1	2,633,189	13	2,242,742	46

Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure

	2012		2011		2010
	(in thousands)
Future cash inflows	$	9,570,652	$	22,012,205	$	19,620,254
Future production costs		(4,737,297)		(8,080,207)		(6,826,915)
Future development costs		(711,050)		(3,425,185)		(3,025,433)
Future income tax expense		(745,251)		(3,366,175)		(3,143,571)
Future net cash flows		3,377,054		7,140,638		6,624,335
10% annual discount for estimated timing of cash flows		(1,326,389)		(3,689,838)		(3,610,585)
Standardized measure of discounted future net cash flows	$	2,050,665	$	3,450,800	$	3,013,750

Schedule Of Analysis Of Changes In Standardized Measure

	2012		2011		2010
	(in thousands)
Standardized measure, beginning of year	$	3,450,800	$	3,013,750	$	1,801,818
Sales and transfers of natural gas and oil produced, net of production costs		(1,443,606)		(1,632,156)		(1,516,571)
Net changes in prices and production costs		(2,604,591)		(381,131)		706,062
Extensions, discoveries, and other additions, net of future production and development costs		549,601		1,163,992		1,205,464
Acquisition of reserves in place		–		30		–
Sales of reserves in place		(157,108)		(11,761)		(6,269)
Revisions of previous quantity estimates		(1,109,409)		34,221		324,284
Accretion of discount		480,315		426,245		230,355
Net change in income taxes		1,079,158		(103,643)		(746,971)
Changes in estimated future development costs		2,475,470		70,492		(10,558)
Previously estimated development costs incurred during the year		61,949		564,894		353,560
Changes in production rates (timing) and other		(731,914)		305,867		672,576
Standardized measure, end of year	$	2,050,665	$	3,450,800	$	3,013,750