Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 8,690	$ 15,502
Restricted cash (Note 7)	4,657	4,592
Certificates of deposit	488	488
Marketable securities	2,047	1,842
Accounts receivable	15,502	18,428
Prepaid income taxes	1,266	2,606
Inventory	23,181	20,507
Parts and supplies, net of allowance of $994 and $1,595, respectively	10,729	9,645
Prepaid expenses	9,667	11,368
Total current assets	76,227	84,978
Property, plant and equipment, at cost:
Land and mineral rights	131,138	130,897
Buildings and equipment	376,265	365,481
Mine development	142,224	140,990
Total property, plant and equipment, at cost	649,627	637,368
Less - accumulated DD&A	(236,440)	(224,730)
Total property, plant and equipment, net	413,187	412,638
Other assets (Note 7)	14,123	14,217
Total assets	507,169	515,499
Current liabilities:
Current portion of bank debt, net (Note 3)	27,230	25,392
Accounts payable and accrued liabilities (Note 6)	29,527	26,421
Total current liabilities	56,757	51,813
Long-term liabilities:
Bank debt, net (Note 3)	134,348	155,655
Deferred income taxes	26,634	26,441
Asset retirement obligations (ARO)	14,777	14,586
Other	9,526	8,130
Total long-term liabilities	185,285	204,812
Total liabilities	242,042	256,625
Redeemable non-controlling interests (Note 14)	4,000	4,000
Stockholders' equity:
Common stock, $.01 par value, 100,000 shares authorized; 30,245 and 29,955 shares outstanding, respectively	302	302
Additional paid-in capital	101,236	100,742
Retained earnings	159,589	153,830
Total stockholders' equity	261,127	254,874
Total liabilities , redeemable noncontrolling interests, and stockholders' equity	507,169	515,499
Sunrise Energy [Member]
Property, plant and equipment, at cost:
Investment in subsidiaries	$ 3,632	$ 3,666