Condensed Statements of Operations (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
REVENUES
Sales of oil and gas	$ 230,760	$ 151,525	$ 418,149	$ 299,332
Sales of electricity	7,964	7,928	14,376	17,861
Gas marketing	3,985	5,004	7,670	13,276
Settlement of Flying J bankruptcy claim		21,992		21,992
Interest and other income, net	803	1,796	931	1,960
TOTAL REVENUES	243,512	188,245	441,126	354,421
EXPENSES
Operating costs - oil and gas production	58,780	46,452	115,863	93,488
Operating costs - electricity generation	6,891	7,839	13,004	17,509
Production taxes	8,350	5,064	15,741	10,269
Depreciation, depletion & amortization - oil and gas production	51,967	43,703	104,076	79,609
Depreciation, depletion & amortization - electricity generation	491	793	992	1,588
Gas marketing	3,674	4,357	7,190	12,142
General and administrative	15,910	12,155	32,201	25,990
Interest	17,712	16,340	33,367	33,788
Realized and unrealized (gain) loss on derivatives, net	(91,808)	(56,057)	35,708	(57,661)
Gain on purchase			(1,046)
Transaction costs on acquisitions		1,908		2,635
Dry hole, abandonment, impairment and exploration	310	266	423	1,636
Bad debt recovery		(38,508)		(38,508)
TOTAL EXPENSES	72,277	44,312	357,519	182,485
Earnings before income taxes	171,235	143,933	83,607	171,936
Income tax provision	66,069	54,910	30,938	65,244
Net earnings	$ 105,166	$ 89,023	$ 52,669	$ 106,692
Basic net earnings per share (in dollars per share)	$ 1.93	$ 1.65	$ 0.97	$ 2.01
Diluted net earnings per share (in dollars per share)	$ 1.90	$ 1.64	$ 0.95	$ 2.00
Dividends per share (in dollars per share)	$ 0.075	$ 0.075	$ 0.15	$ 0.15