Asset Retirement Obligations

12 Months Ended

Dec. 31, 2016

Asset Retirement Obligation Disclosure [Abstract]

(9)	Asset Retirement Obligations

Our asset retirement obligations primarily represent the present value of the estimated 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 life. The inputs are calculated based on historical data as well as current estimated costs. The following is a reconciliation of our liability for plugging and abandonment costs as of December 31, 2016 and 2015 (in thousands):


	2016			2015
Beginning of period	$	264,137		$	287,463
Liabilities incurred		2,694			4,595
Acquisitions		21,900			1,584
Liabilities settled		(11,511	)		(18,828	)
Disposition of wells		(10,540	)		(45,845	)
Accretion expense		18,021			19,163
Change in estimate		(26,758	)		16,005
End of period		257,943			264,137
Less current portion		(7,271	)		(15,071	)
Long-term asset retirement obligations	$	250,672		$	249,066

Accretion expense is recognized as an increase to depreciation, depletion and amortization expense in the accompanying consolidated statements of operations.