CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
REVENUES
Oil and gas sales	$ 403,143		$ 405,216		$ 326,320
Midstream services	1,974		1,408		1,631
Drilling rig services	15,858		4,060		0
Other operating revenues	2,077		15,744		3,680
Total revenues	423,052		426,428		331,631
COSTS AND EXPENSES
Production	124,950		101,099		83,146
Exploration:
Abandonments and impairments	4,222		20,840		9,074
Seismic and other	11,591		5,363		6,046
Midstream services	1,228		1,039		1,209
Drilling rig services	17,423		5,064		1,198
Depreciation, depletion and amortization	142,687		104,880		101,145
Impairment of property and equipment	5,944		10,355		11,908
Accretion of asset retirement obligations	3,696		2,757		2,623
General and administrative	30,485		41,560		35,588
Other operating expenses	1,033		1,666		1,750
Total costs and expenses	343,259		294,623		253,687
Operating income	79,793		131,805		77,944
OTHER INCOME (EXPENSE)
Interest expense	(38,664)		(32,919)		(24,402)
Loss on early extinguishment of long-term debt	0		(5,501)		0
Gain (loss) on derivatives	14,448		47,027		722
Other	1,534		5,553		3,308
Total other income (expense)	(22,682)		14,160		(20,372)
Income (loss) before income taxes	57,111		145,965		57,572
Income tax (expense) benefit	(22,008)		(52,142)		(20,634)
NET INCOME (LOSS)	$ 35,103		$ 93,823		$ 36,938
Net income (loss) per common share:
Basic (in dollars per share)	$ 2.89	[1]	$ 7.72	[1]	$ 3.04
Diluted (in dollars per share)	$ 2.89	[1]	$ 7.71	[1]	$ 3.04
Weighted average common shares outstanding:
Basic shares	12,164		12,161		12,148
Diluted shares	12,164		12,162		12,148

[1] The sum of the individual quarterly net income (loss) per share amounts may not agree to the total for the year since each period’s computation is based on the weighted average number of common shares outstanding during each period.