Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 16,264	$ 22,791
Accounts receivable	42,929	40,203
Allowance for doubtful accounts	(378)	(261)
Accounts receivable, net	42,551	39,942
Inventories:
Finished goods	17,778	21,738
Raw materials	1,795	1,573
Total inventories	19,573	23,311
Supplies, prepaid items and other:
Prepaid insurance	12,315	11,837
Precious metals	6,787	5,568
Supplies	25,288	24,689
Other	6,802	2,735
Total supplies, prepaid items and other	51,192	44,829
Total current assets	129,580	130,873
Property, plant and equipment, net	891,198	936,474
Other assets:
Operating lease assets	26,403	15,330
Intangible and other assets, net	6,121	5,812
Total other assets	32,524	21,142
Total assets	1,053,302	1,088,489
Current liabilities:
Accounts payable	46,551	58,477
Short-term financing	13,576	9,929
Accrued and other liabilities	30,367	25,484
Current portion of long-term debt	16,801	9,410
Total current liabilities	107,295	103,300
Long-term debt, net	467,389	449,634
Noncurrent operating lease liabilities	19,845	11,404
Other noncurrent accrued and other liabilities	6,090	6,214
Deferred income taxes	30,939	35,717
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $.10 par value; 75,000,000 shares authorized, 31,283,210 shares issued	3,128	3,128
Capital in excess of par value	198,215	196,833
Retained earnings (accumulated deficit)	(41,487)	57,632
Stockholders equity including treasury stock	162,856	260,593
Less treasury stock, at cost:
Common stock, 2,074,565 shares (2,009,566 shares at December 31, 2019)	13,213	13,266
Total stockholders' equity	149,643	247,327
Total Liabilities and Stockholders' equity	1,053,302	1,088,489
Series E Preferred Stock [Member]
Redeemable preferred stocks:
Redeemable preferred stock, value	272,101	234,893
Series B Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value	2,000	2,000
Series D Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value	$ 1,000	$ 1,000