Consolidated Statements Of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
OIL AND GAS REVENUES	$ 111,901	$ 80,715
COSTS AND EXPENSES
Lease operating	10,195	8,423
Production tax	4,513	3,099
Ad valorem tax	1,860	3,615
Depreciation, depletion and amortization	45,590	31,561
General and administrative (inclusive of stock-based compensation expense of $6,483 and $4,016 for the three months ended March 31, 2013 and 2012, respectively)	16,173	11,535
Accretion related to asset retirement obligations	107	102
TOTAL COSTS AND EXPENSES	78,438	58,335
OPERATING INCOME	33,463	22,380
OTHER INCOME AND EXPENSES
Gain (loss) on derivative instruments, net	(14,554)	3,803
Interest expense	(21,752)	(16,457)
Capitalized interest	6,776	6,023
Other income, net	40	212
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	3,973	15,961
INCOME TAX EXPENSE	(1,449)	(5,285)
NET INCOME FROM CONTINUING OPERATIONS	2,524	10,676
NET INCOME (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	23,658	(1,253)
NET INCOME	$ 26,182	$ 9,423
NET INCOME PER COMMON SHARE - BASIC
Net income from continuing operations - basic (in dollars per share)	$ 0.06	$ 0.27
Net income (loss) from discontinued operations - basic (in dollars per share)	$ 0.60	$ (0.03)
Net income per share, basic (in dollars per share)	$ 0.66	$ 0.24
NET INCOME PER COMMON SHARE - DILUTED
Net income from continuing operations - diluted (in dollars per share)	$ 0.06	$ 0.27
Net income (loss) from discontinued operations - diluted (in dollars per share)	$ 0.59	$ (0.03)
Net income per share, diluted (in dollars per share)	$ 0.65	$ 0.24
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)	39,778	39,445
Diluted (in shares)	40,333	39,917