ASSET RETIREMENT OBLIGATIONS (Tables)

3 Months Ended

Mar. 31, 2019

ASSET RETIREMENT OBLIGATIONS [Abstract]

Asset Retirement Obligations Operating Costs

	Three Months Ended
	March 31
in thousands	2019	2018
ARO Operating Costs
Accretion	$        2,733	$        2,684
Depreciation	1,841	1,337
Total	$        4,574	$        4,021

Reconciliations of Asset Retirement Obligations

	Three Months Ended
	March 31
in thousands	2019	2018
Asset Retirement Obligations
Balance at beginning of year	$     225,726	$     218,117
Liabilities incurred	0	0
Liabilities settled	(3,578)	(6,021)
Accretion expense	2,733	2,684
Revisions, net	305	(71)
Balance at end of period	$     225,186	$     214,709