Consolidated Statement of Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue and Other Income:
Revenue	$ 323,462	$ 293,557
Costs and expenses:
Operating costs and expenses	247,866	215,363
DD&A	48,572	44,167
ARO accretion	1,272	1,167
Exploration costs	1,225	1,185
SG&A	12,848	11,841
Total Interest	15,998	16,288
Asset impairment	77,882
Total costs and expenses	405,663	290,011
Income (loss) before income taxes	(82,201)	3,546
Income tax benefit
Current	(525)	(1,788)
Deferred	(21,822)	(2,287)
Total income tax benefit	(22,347)	(4,075)
Net income (loss)	$ (59,854)	$ 7,621
Net income (loss) per share: (Note 11)
Basic and diluted (in Dollars per share)	$ (1.95)	$ 0.25
Weighted average shares outstanding:
Basic and diluted (in Shares)	30,253	30,074
Bank interest	$ 11,511	$ 11,883
Change in interest rate swap valuation	2,186	2,182
Amortization of debt issuance costs	2,095	2,024
Other	206	199
Total non-cash interest	4,487	4,405
Coal Sales [Member]
Revenue and Other Income:
Revenue	317,436	291,783
Other Revenue [Member]
Revenue and Other Income:
Revenue	$ 6,026	$ 1,774