Condensed Consolidated Statements of Income (Loss) and Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenue
Production	$ 113,895		$ 121,121		$ 229,571		$ 253,735
Sales of purchased natural gas	19,520		18,685		36,742		35,243
Net derivative gains (losses)	(16,357)		34,837		(58,390)		3,468
Other	974		854		1,895		1,755
Total revenue	118,032		175,497		209,818		294,201
Operating expense
Lease operating	18,690		20,213		37,446		45,108
Gathering, processing and transportation	34,921		36,674		67,704		76,498
Production and ad valorem taxes	4,305		5,300		8,489		10,784
Costs of purchased natural gas	19,514		18,679		36,706		35,197
Depletion, depreciation and accretion	14,659		15,265		28,615		33,521
General and administrative	11,485		16,875		26,805		33,038
Other operating	922		769		1,571		2,205
Total expense	104,496		113,775		207,336		236,351
Operating income (loss)	13,536		394,894		2,482		391,022
Other income - net	(1,427)		(15,105)		(1,359)		(15,255)
Fortune Creek accretion	(3,602)		(4,827)		(8,003)		(9,672)
Interest expense	(41,233)		(127,238)		(82,028)		(171,180)
Income (loss) before income taxes	(32,726)		247,724		(88,908)		194,915
Income tax (expense) benefit	(3,369)		(5,201)		(6,020)		(12,097)
Net Income (Loss) Attributable to Parent	(36,095)		242,523		(94,928)		182,818
Reclassification adjustments related to settlements of derivative contracts into production revenue- net of income tax	(5,121)		(11,287)		(12,971)		(26,042)
Foreign currency translation adjustment	5,014		(3,580)		759		(3,278)
Other comprehensive income (loss)	(107)		(14,867)		(12,212)		(29,320)
Comprehensive income (loss)	(36,202)		227,656		(107,140)		153,498
Earnings (loss) per common share - basic	$ (0.21)		$ 1.37		$ (0.55)		$ 1.04
Earnings (loss) per common share - diluted	$ (0.21)	[1]	$ 1.37	[1]	$ (0.55)	[1]	$ 1.04	[1]
Tokyo Gas [Member]
Operating expense
Gain (Loss) on Disposition of Oil and Gas and Timber Property	$ 0		$ 333,172		$ 0		$ 333,172

[1] For the three months ended June 30, 2014, 6.6 million shares associated with our stock options and 0.3 million shares associated with our unvested RSUs were antidilutive and, therefore, excluded from the diluted share calculations. For the three months ended June 30, 2013, 5.3 million shares associated with our stock options and 1.0 million shares associated with our unvested RSUs were antidilutive and, therefore, excluded from the diluted share calculations. For the six months ended June 30, 2014, 6.6 million shares associated with our stock options and 0.3 million shares associated with our unvested RSUs were antidilutive and, therefore, excluded from the diluted share calculations. For the six months ended June 30, 2013, 5.2 million shares associated with our stock options and 1.0 million shares associated with our unvested RSUs were antidilutive and, therefore, excluded from the diluted share calculations.