ASSET RETIREMENT OBLIGATIONS (Tables)

3 Months Ended

Mar. 31, 2016

ASSET RETIREMENT OBLIGATIONS [Abstract]

Asset Retirement Obligations Operating Costs

	Three Months Ended
	March 31
in thousands	2016	2015
ARO Operating Costs
Accretion	$        2,755	$        2,851
Depreciation	1,693	1,433
Total	$        4,448	$        4,284

Reconciliations of Asset Retirement Obligations

	Three Months Ended
	March 31
in thousands	2016	2015
Asset Retirement Obligations
Balance at beginning of year	$     226,594	$     226,565
Liabilities incurred	0	1,820
Liabilities settled	(4,868)	(6,730)
Accretion expense	2,755	2,851
Revisions, net	(3,900)	14,183
Balance at end of period	$     220,581	$     238,689