Asset Retirement Obligations

12 Months Ended

Dec. 31, 2012

Asset Retirement Obligation Disclosure [Abstract]

Changes in asset retirement obligations (“ARO”) for 2012 and 2011 are as follows:



	2012			2011
	(In thousands)
Beginning of year	$	40,794		$	40,444
Additional ARO from new properties	7,868			1,526
Sales or abandonments of properties	(2,184		)	(4,425		)
Accretion expense	3,696			2,757
Revisions of previous estimates	1,303			492
End of year	$	51,477		$	40,794

Our ARO is measured using primarily Level 3 inputs. The significant unobservable inputs to this fair value measurement include estimates of plugging, abandonment and remediation costs, inflation rate and well life. The inputs are calculated based on historical data as well as current estimated costs.

- Definition

The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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