Summary of Signigicant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Property and Equipment

The following is a detailed breakout of our “Property and Equipment” balances.

(in thousands)	December 31, 2012			December 31, 2011
Property and Equipment
Proved oil and gas properties	$	5,058,524		$	4,343,867
Unproved oil and gas properties	92,579			84,146
Furniture, fixtures, and other equipment	41,690			38,832
Less – Accumulated depreciation, depletion, and amortization	(2,847,773		)	(2,599,079		)
Property and Equipment, Net	$	2,345,020		$	1,867,766

Accounts Payable and Accrued Liabilities

The “Accounts payable and accrued liabilities” balances on the accompanying consolidated balance sheets are summarized below (in thousands):

	December 31, 2012		December 31, 2011
Trade accounts payable (1)	$	31,128	$	42,080
Accrued operating expenses	14,647		15,833
Accrued payroll costs	12,297		14,345
Asset retirement obligation – current portion	7,134		9,279
Accrued taxes	5,373		7,604
Other payables	4,799		6,825
Total accounts payable and accrued liabilities	$	75,378	$	95,966

(1) Included in “trade accounts payable” are liabilities of approximately $13.3 million and $18.7 million at December 31, 2012 and 2011, respectively, for outstanding checks.

Accumulated other comprehensive income and related tax effects

The components of accumulated other comprehensive income and related tax effects for 2012 were as follows (in thousands):

	Gross Value			Tax Effect			Net of Tax Value
Other comprehensive loss at December 31, 2011	$	—		$	—		$	—
Change in fair value of cash flow hedges	1,210			440			770
Effect of cash flow hedges settled during the period	(1,210		)	(440		)	(770		)
Other comprehensive loss at December 31, 2012	$	—		$	—		$	—

Roll-forward of our asset retirement obligations

The following provides a roll-forward of our asset retirement obligation (in thousands):

Asset Retirement Obligation as of December 31, 2009	$	64,236
Accretion expense	3,956
Liabilities incurred for new wells and facilities construction	1,287
Reductions due to abandoned wells	(749		)
Revisions in estimates	10,149
Asset Retirement Obligation as of December 31, 2010	$	78,879
Accretion expense	4,570
Liabilities incurred for new wells and facilities construction	590
Reductions due to sold and abandoned wells	(28,194		)
Revisions in estimates	20,548
Asset Retirement Obligation as of December 31, 2011	$	76,393
Accretion expense	5,121
Liabilities incurred for new wells and facilities construction	2,195
Reductions due to abandoned wells	(2,824		)
Revisions in estimates	5,892
Asset Retirement Obligation as of December 31, 2012	$	86,777