ASSET RETIREMENT OBLIGATIONS (Tables)

9 Months Ended

Sep. 30, 2016

ASSET RETIREMENT OBLIGATIONS [Abstract]

Asset Retirement Obligations Operating Costs

	Three Months Ended		Nine Months Ended
	September 30		September 30
in thousands	2016	2015	2016	2015
ARO Operating Costs
Accretion	$        2,692	$        2,766	$        8,163	$        8,553
Depreciation	1,469	1,681	4,783	4,683
Total	$        4,161	$        4,447	$      12,946	$      13,236

Reconciliations of Asset Retirement Obligations

	Three Months Ended		Nine Months Ended
	September 30		September 30
in thousands	2016	2015	2016	2015
Asset Retirement Obligations
Balance at beginning of period	$     217,043	$     234,919	$     226,594	$     226,565
Liabilities incurred	0	0	505	6,159
Liabilities settled	(3,937)	(5,318)	(14,256)	(13,318)
Accretion expense	2,692	2,766	8,163	8,553
Revisions, net	(1,112)	2,313	(6,320)	6,721
Balance at end of period	$     214,686	$     234,680	$     214,686	$     234,680