Asset Retirement Obligation (Tables)

6 Months Ended

Jun. 30, 2016

Asset Retirement Obligation Disclosure [Abstract]

Changes to Company's Asset Retirement Obligations

The following table describes the changes to the Company’s asset retirement obligations during the six months ended June 30, 2016 and 2015 (in thousands):

	Six Months Ended
	June 30,
	2016			2015
Balance at beginning of year	$	5,692		$	5,301
Liabilities incurred		66			271
Liabilities settled		(71	)		(65	)
Accretion expense		84			86
Revision in estimated costs of plugging oil and natural gas wells		43			—
Asset retirement obligation at end of period	$	5,814		$	5,593