Provision (Benefit) for Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Provision (Benefit) for Income Taxes [Abstract]

Summary of income (Loss) from continuing operations before taxes

	Year Ended December 31,
	2011		2010		2009
Income (Loss) from Continuing Operations Before Income Taxes	$	135,104	$	74,308	($	64,617	)

Summary of consolidated income tax provision (benefit)

	Year Ended December 31,
	2011		2010			2009
Current	$	1,616	($	2,957	)	($	10,792	)
Deferred		48,878		30,790			(14,749	)
Total	$	50,494	$	27,833		($	25,541	)

Reconciliations of income taxes computed using the U.S. Federal statutory rate to the effective income tax rates

	Year Ended December 31,
	2011			2010			2009
Income taxes (or benefits) computed at U.S. statutory rate (35%)	$	47,282		$	26,008		($	22,616	)
State tax provisions (benefits), net of federal benefits		1,505			641			(1,956	)
Cumulative impact of adjustments to net state income tax rate		(2,663	)		(1,718	)		—
Valuation allowance of carryover tax assets		2,273			1,681			(1,082	)
Non-deductible equity compensation		1,537			867			105
Other, net		560			354			8
Provision (benefit) for income taxes	$	50,494		$	27,833		($	25,541	)
Effective rate		37.4	%		37.5	%		39.5	%

Tax effects of temporary differences representing the net deferred tax asset (liability)

	2011			2010
Deferred tax assets:
Federal net operating losses (“NOLs”)	$	54,954		$	30,715
NOLs for excess stock-based compensation		(9,450	)		(7,590	)
Alternative minimum tax credits		3,451			2,092
Carryover items, net of valuation allowance		8,617			8,823
Unrealized stock compensation		7,151			5,519
Other		7,580			7,026
Total deferred tax assets	$	72,303		$	46,585
Deferred tax liabilities:
Oil and gas exploration and development costs	($	270,158	)	($	195,454	)
Other		(2,109	)		(2,349	)
Total deferred tax liabilities	($	272,267	)	($	197,803	)
Net deferred tax liabilities	($	199,964	)	($	151,218	)
Net current deferred tax assets		6,603			6,347
Net non-current deferred tax liabilities	($	206,567	)	($	157,565	)