CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 14,232	$ 16,264
Accounts receivable	60,503	42,929
Allowance for doubtful accounts	(378)	(378)
Accounts receivable, net	60,125	42,551
Inventories:
Finished goods	17,649	17,778
Raw materials	1,569	1,795
Total inventories	19,218	19,573
Supplies, prepaid items and other:
Prepaid insurance	10,051	12,315
Precious metals	6,674	6,787
Supplies	25,406	25,288
Other	3,258	6,802
Total supplies, prepaid items and other	45,389	51,192
Total current assets	138,964	129,580
Property, plant and equipment, net	882,816	891,198
Other assets:
Operating lease assets	27,671	26,403
Intangible and other assets, net	5,546	6,121
Total other assets	33,217	32,524
Total assets	1,054,997	1,053,302
Current liabilities:
Accounts payable	57,360	46,551
Short-term financing	8,157	13,576
Accrued and other liabilities	40,722	30,367
Current portion of long-term debt	18,082	16,801
Total current liabilities	124,321	107,295
Long-term debt, net	463,673	467,389
Noncurrent operating lease liabilities	20,244	19,845
Other noncurrent accrued and other liabilities	6,333	6,090
Deferred income taxes	31,266	30,939
Commitments and contingencies (Note 5)
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	193,618	198,215
Accumulated deficit	(64,788)	(41,487)
Stockholders equity including treasury stock	134,958	162,856
Less treasury stock, at cost:
Common stock, 1,245,461 shares (2,074,565 shares at December 31, 2020)	7,921	13,213
Total stockholders' equity	127,037	149,643
Total Liabilities and Stockholders' equity	1,054,997	1,053,302
Series E Preferred Stock [Member]
Redeemable preferred stocks:
Redeemable preferred stock, value	282,123	272,101
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