Natural Gas and Oil Producing Activities (Tables)

12 Months Ended

Dec. 31, 2011

Natural Gas And Oil Producing Activities Abstract

Capitalized Costs of Gas and Oil Properties and the Related Accumulated Depreciation, Depletion and Amortization

	2011		2010
	(in thousands)
Proved properties	$    8,601,818		$    7,037,746
Unproved properties	942,890	(1)	712,117	(1)
Total capitalized costs	9,544,708		7,749,863
Less:  Accumulated depreciation, depletion and amortization	4,092,410		3,444,477
Net capitalized costs	$    5,452,298		$    4,305,386

Composition of Net Unevaluated Costs Excluded from Amortization

	2011	2010	2009	Prior	Total
	(in thousands)
Property acquisition costs	$     254,622	$     143,165	$       44,513	$       110,767	$    553,067
Exploration and development costs	190,240	20,844	29,527	67,335	307,946
Capitalized interest	14,651	12,901	10,261	44,064	81,877
	$     459,513	$     176,910	$     84,301	$    222,166	$    942,890

Capitalized Costs Incurred in Natural Gas and Oil Property Acquisition, Exploration and Development Activities

	2011		2010		2009
	(in thousands, except per Mcfe amounts)
Proved property acquisition costs	$            17		$                0		$          4,372
Unproved property acquisition costs	262,886	(1)	229,909	(1)	115,217
Exploration costs	63,419	(2)	27,062	(2)	52,178
Development costs	1,633,784		1,524,453		1,358,109
Capitalized costs incurred	1,960,106		1,781,424		1,529,876
Full cost pool amortization per Mcfe	$            1.30		$            1.34		$            1.51

Results of Operations from Natural Gas and Oil Producing Activities

	2011	2010	2009
	(in thousands)
Sales	$ 2,100,488	$ 1,890,444	$ 1,593,231
Production (lifting) costs	(469,153)	(376,939)	(259,588)
Depreciation, depletion and amortization	(666,107)	(561,003)	(474,014)
Impairment of natural gas and oil properties	0	0	(907,812)
	965,228	952,502	(48,183)
Provision (benefit) for income taxes	376,049	371,281	(15,650)
Results of operations	$   589,179	$    581,221	$    (32,533)

Changes in Proved Natural Gas and Oil Reserves

	2011		2010		2009
	Natural		Natural		Natural
	Gas	Oil	Gas	Oil	Gas	Oil
	(MMcf)	(MBbls)	(MMcf)	(MBbls)	(MMcf)	(MBbls)
Proved reserves, beginning of year	4,929,980	1,219	3,650,303	1,059	2,175,528	1,507
Revisions of previous estimates	34,505	(125)	309,292	50	94,930	(346)
Extensions, discoveries and other additions	1,459,428	2	1,429,439	281	1,683,264	22
Production	(499,433)	(97)	(403,636)	(171)	(299,698)	(124)
Acquisition of reserves in place	13	0	0	0	1,795	0
Disposition of reserves in place	(37,286)	(3)	(55,418)	0	(5,516)	0
Proved reserves, end of year	5,887,207	996	4,929,980	1,219	3,650,303	1,059
Proved developed reserves:
Beginning of year	2,687,238	1,173	1,972,767	1,028	1,336,370	1,352
End of year	3,254,018	983	2,687,238	1,173	1,972,767	1,028
Proved undeveloped reserves:
Beginning of year	2,242,742	46	1,677,536	31	839,158	155
End of year	2,633,189	13	2,242,742	46	1,677,536	31

Standardized Measures of Discounted Future Net Cash Flows Relating to Proved Natural Gas and Oil Reserves

	2011	2010	2009
	(in thousands)
Future cash inflows	$ 22,012,205	$ 19,620,254	$ 12,533,868
Future production costs	(8,080,207)	(6,826,915)	(4,488,884)
Future development costs	(3,425,185)	(3,025,433)	(2,367,206)
Future income tax expense	(3,366,175)	(3,143,571)	(1,569,242)
Future net cash flows	7,140,638	6,624,335	4,108,536
10% annual discount for estimated timing of cash flows	(3,689,838)	(3,610,585)	(2,306,718)
Standardized measure of discounted future net cash flows	$ 3,450,800	$  3,013,750	$  1,801,818

Analysis of Changes in the Standardized Measure

	2011	2010	2009
	(in thousands)
Standardized measure, beginning of year	$  3,013,750	$  1,801,818	$  2,109,262
Sales and transfers of natural gas and oil produced, net of production costs	(1,632,156)	(1,516,571)	(1,330,256)
Net changes in prices and production costs	(381,131)	706,062	(1,321,404)
Extensions, discoveries, and other additions, net of future production and development costs	1,163,992	1,205,464	976,449
Acquisition of reserves in place	30	0	1,878
Sales of reserves in place	(11,761)	(6,269)	(4,430)
Revisions of previous quantity estimates	34,221	324,284	88,261
Accretion of discount	426,245	230,355	302,439
Net change in income taxes	(103,643)	(746,971)	413,399
Changes in estimated future development costs	70,492	(10,558)	204,005
Previously estimated development costs incurred during the year	564,894	353,560	218,625
Changes in production rates (timing) and other	305,867	672,576	143,590
Standardized measure, end of year	$  3,450,800	$  3,013,750	$  1,801,818