Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2012

Summary of Significant Accounting Policies [Abstract]

Property and Equipment

(in thousands)	March 31, 2012			December 31, 2011
Property and Equipment
Proved oil and gas properties	$	4,521,651		$	4,343,867
Unproved oil and gas properties		87,327			84,146
Furniture, fixtures, and other equipment		39,709			38,832
Less – Accumulated depreciation, depletion, and amortization		(2,660,839	)		(2,599,079	)
Property and Equipment, Net	$	1,987,848		$	1,867,766

Accounts Payable and Accrued Liabilities

	March 31, 2012		December 31, 2011
Trade accounts payable (1)	$	39,219	$	42,080
Accrued operating expenses		15,540		15,833
Accrued payroll costs		4,957		14,345
Asset retirement obligation – current portion		9,303		9,279
Accrued taxes		7,446		7,604
Other payables		2,333		6,825
Total accounts payable and accrued liabilities	$	78,798	$	95,966

(1) Included in “trade accounts payable” are liabilities of approximately $22.1 million and $18.7 million at March 31, 2012 and December 31, 2011, respectively, for outstanding checks. This represents the amounts by which checks were issued, but not presented by vendors to the Company’s banks for collection, exceeded balances in the applicable disbursement bank accounts.

Accumulated other comprehensive income and related tax effects

	Gross Value		Tax Effect			Net of Tax Value
Other comprehensive loss at December 31, 2011	$	—	$	—		$	—
Change in fair value of cash flow hedges		212		(77	)		135
Effect of cash flow hedges settled during the period		198		(72	)		126
Other comprehensive income at March 31, 2012	$	410	($	149	)	$	261

Roll-forward of our asset retirement obligation

	2012			2011
Asset Retirement Obligation recorded as of January 1	$	76,393		$	78,879
Accretion expense		1,112			1,136
Liabilities incurred for new wells and facilities construction		282			139
Reductions due to sold and abandoned wells		(79	)		(32	)
Revisions in estimates		1,147			(1,385	)
Asset Retirement Obligation as of March 31	$	78,855		$	78,737