Condensed Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
REVENUES
Oil and natural gas sales	$ 232,916	$ 225,325	$ 688,350	$ 643,474
Electricity sales	9,514	9,826	21,354	24,202
Natural gas marketing	1,939	3,612	5,378	11,282
Gain on sale of assets	170	0	1,770	0
Other income	286	463	1,678	1,394
TOTAL REVENUES	244,825	239,226	718,530	680,352
EXPENSES
Operating costs—oil and natural gas production	70,778	61,979	187,491	177,842
Operating costs- electricity generation	4,727	6,965	14,000	19,969
Production taxes	9,700	9,185	30,048	24,926
Depreciation, depletion & amortization			160,251	160,136
Natural gas marketing	1,753	3,285	4,917	10,475
General and administrative	17,767	14,922	53,473	47,123
Interest	20,572	19,928	61,446	53,295
Impairment of oil and natural gas properties	0	0	67	0
Dry hole, abandonment, impairment and exploration	2,729	196	7,283	619
Gain on purchase	0	0	0	(1,046)
Extinguishment of debt	0	14,391	41,545	14,391
Realized and unrealized loss (gain) on derivatives, net	28,287	(162,145)	(56,314)	(126,437)
TOTAL EXPENSES	215,661	23,774	504,207	381,293
Earnings before income taxes	29,164	215,452	214,323	299,059
Income tax provision	11,038	81,451	81,283	112,389
Net earnings	18,126	134,001	133,040	186,670
Basic net earnings per share (in dollars per share)	$ 0.33	$ 2.45	$ 2.41	$ 3.42
Diluted net earnings per share (in dollars per share)	$ 0.33	$ 2.42	$ 2.39	$ 3.38
Dividends per share (in dollars per share)	$ 0.08	$ 0.08	$ 0.24	$ 0.23
Oil and Natural Gas Properties, Buildings, and Equipment
EXPENSES
Depreciation, depletion & amortization	58,887	54,581	158,869	158,657
Electricity Generation
EXPENSES
Depreciation, depletion & amortization	$ 461	$ 487	$ 1,382	$ 1,479