Asset Retirement Obligations

6 Months Ended

Jun. 30, 2018

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

9. ASSET RETIREMENT OBLIGATIONS

The changes in asset retirement obligations for the six months ended June 30, 2018 and the year ended December 31, 2017 are as follows:

	Six months ended			Year ended
	June 30, 2018			December 31, 2017
	(in thousands)
Balance at beginning of period (including current portion)	$	18,662		$	19,108
Accretion expense		639			1,493
Adjustment resulting from disposal of property		-			(223	)
Adjustments to the liability from annual recosting and other		-			(1,656	)
Liabilities settled		(158	)		(60	)
Balance at end of period		19,143			18,662
Less current portion of asset retirement obligation		(498	)		(498	)
Long-term portion of asset retirement obligation	$	18,645		$	18,164