Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
REVENUE AND OTHER INCOME:
Coal sales		$ 242,084	$ 317,436
Other operating income		3,211	6,026
Total revenue and other income		245,295	323,462
COSTS AND EXPENSES:
Operating costs and expenses		185,957	247,866
DD&A		39,644	48,572
ARO accretion		1,381	1,272
Exploration costs		768	1,225
SG&A		11,594	12,848
Interest	[1]	13,030	15,998
Asset impairment		1,799	77,882
Total costs and expenses		254,173	405,663
LOSS BEFORE INCOME TAXES		(8,878)	(82,201)
Current		(598)	(525)
Deferred		(2,060)	(21,822)
Total income tax benefit		(2,658)	(22,347)
NET LOSS		$ (6,220)	$ (59,854)
NET LOSS PER SHARE:
Basic and diluted (in dollars per share)		$ (0.20)	$ (1.95)
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic and diluted (in shares)		30,446	30,253
(1) Bank interest		$ 10,653	$ 11,511
Non-cash interest:
Change in interest rate swap valuation		68	2,186
Amortization of debt issuance costs		2,296	2,095
Other		13	206
Total non-cash interest		2,377	4,487
Total interest	[1]	$ 13,030	$ 15,998

[1] Bank interest