Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of stock option grants under prior stock option plans

A summary of activity associated with the Company’s Stock Option Plan for the six months ended June 30, 2012, is presented in the following table:

	Shares		Weighted- Average Exercise Price		Aggregate  Intrinsic Value (in thousands)
Outstanding, at beginning of year	508,214		$	13.86	$	30,109
Exercised	(108,299	)	$	12.36	$	6,667
Forfeited	—		$	—
Outstanding, at end of quarter	399,915		$	14.26	$	13,937
Vested and exercisable, at end of quarter	399,915		$	14.26	$	13,937

Summary of cash payments made or accrued under the Net Profits Plan

Cash payments made or accrued under the Net Profits Interest Bonus Plan (“Net Profits Plan”) that have been recorded as either general and administrative expense or exploration expense are presented in the table below:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2012		2011		2012		2011
	(in thousands)
General and administrative expense	$	3,682	$	5,261	$	8,094	$	10,591
Exploration expense	493		585		1,018		1,062
Total	$	4,175	$	5,846	$	9,112	$	11,653