Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 6,406	$ 15,502
Restricted cash (Note 10)	4,576	4,592
Certificates of deposit	245	488
Marketable securities	2,074	1,842
Accounts receivable	20,239	18,428
Prepaid Income Taxes Current	1,188	2,606
Inventory	30,923	20,507
Parts and supplies, net of allowance of $994 and $1,595, respectively	11,534	9,645
Prepaid expenses	4,101	11,368
Total current assets	81,286	84,978
Property, plant and equipment, at cost:
Land and mineral rights	131,921	130,897
Building And Equipment Gross	384,660	365,481
Mine development	144,642	140,990
Total property, plant and equipment, at cost	661,223	637,368
Less - accumulated DD&A	(247,408)	(224,730)
Total property, plant and equipment, net	413,815	412,638
Investment in subsidiaries	3,500	3,666
Other assets (Note 5)	14,294	14,217
Total assets	512,895	515,499
Current liabilities:
Current portion of bank debt, net (Note 3)	29,067	25,392
Accounts payable and accrued liabilities (Note 6)	32,094	26,421
Total current liabilities	61,161	51,813
Long-term liabilities:
Bank debt, net (Note 3)	137,703	155,655
Deferred income taxes	26,747	26,441
Asset retirement obligations (ARO)	15,013	14,586
Other	11,219	8,130
Total long-term liabilities	190,682	204,812
Total liabilities	251,843	256,625
Redeemable noncontrolling interests (Note 14)	4,000	4,000
Stockholders' equity:
Common stock, $.01 par value, 100,000 shares authorized; 30,247 and 30,245 outstanding	302	302
Additional paid-in capital	101,747	100,742
Retained earnings	155,003	153,830
Total stockholders' equity	257,052	254,874
Total liabilities , redeemable noncontrolling interests, and stockholders' equity	$ 512,895	$ 515,499