Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2018

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligation

The following is a reconciliation of our liability for plugging and abandonment costs as of December 31, 2018 and 2017 (in thousands):

	2018			2017
Beginning of period	$	276,855		$	257,943
Liabilities incurred		3,376			7,724
Acquisitions		13,438			—
Liabilities settled		(5,052	)		(7,965	)
Disposition of wells		(13,332	)		(8,078	)
Accretion expense		25,456			14,711
Change in estimate		12,013			12,520
End of period		312,754			276,855
Less current portion		(5,485	)		(6,327	)
Long-term asset retirement obligations	$	307,269		$	270,528