Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2020

Asset Retirement Obligation Disclosure [Abstract]

Changes in Asset Retirement Obligation Liabilities

The components of the changes in the asset retirement obligation liabilities were:

(Dollars in thousands)	Short-Term Portion			Long-Term Portion			Total
Balance at January 1, 2020	$	90		$	6,061		$	6,151
Accretion	(9		)	127			118
Amounts paid	(27		)	—			(27		)
Increases	—			—			—
Reclassifications	79			(79		)	—
Balance at March 31, 2020	$	133		$	6,109		$	6,242