Asset Retirement Obligations

3 Months Ended

Mar. 31, 2015

Asset Retirement Obligation Disclosure [Abstract]

(9) ASSET RETIREMENT OBLIGATIONS

Our asset retirement obligations primarily represent the estimated present value of the amounts we will incur to plug, abandon and remediate our producing properties at the end of their productive lives. Significant inputs used in determining such obligations include estimates of plugging and abandonment costs, estimated future inflation rates and well lives. The inputs are calculated based on historical data as well as current estimated costs. In the first quarter 2015, we increased our estimated abandonment costs on certain of our water impoundments and changed well lives for certain wells in Pennsylvania. A reconciliation of our liability for plugging and abandonment costs for the three months ended March 31, 2015 is as follows (in thousands):

	Three Months Ended March 31, 2015
Beginning of period	$	287,463
Liabilities incurred		1,460
Liabilities settled		(3,257	)
Disposition of wells		(4,112	)
Accretion expense		4,723
Change in estimate		14,353
End of period		300,630
Less current portion		(17,689	)
Long-term asset retirement obligations	$	282,941

Accretion expense is recognized as a component of depreciation, depletion and amortization expense in the accompanying statements of consolidated income.