CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 56,513	$ 22,791
Accounts receivable	42,569	40,203
Allowance for doubtful accounts	(397)	(261)
Accounts receivable, net	42,172	39,942
Inventories:
Finished goods	12,968	21,738
Raw materials	1,364	1,573
Total inventories	14,332	23,311
Supplies, prepaid items and other:
Prepaid insurance	5,195	11,837
Precious metals	7,682	5,568
Supplies	25,221	24,689
Other	1,660	2,735
Total supplies, prepaid items and other	39,758	44,829
Total current assets	152,775	130,873
Property, plant and equipment, net	913,441	936,474
Other assets:
Operating lease assets	20,895	15,330
Intangible and other assets, net	7,554	5,812
Total other assets	28,449	21,142
Total assets	1,094,665	1,088,489
Current liabilities:
Accounts payable	45,245	58,477
Short-term financing	3,834	9,929
Accrued and other liabilities	27,768	25,484
Current portion of long-term debt	11,492	9,410
Total current liabilities	88,339	103,300
Long-term debt, net	487,552	449,634
Noncurrent operating lease liabilities	15,956	11,404
Other noncurrent accrued and other liabilities	5,244	6,214
Deferred income taxes	34,056	35,717
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	197,566	196,833
Retained earnings	19,810	57,632
Stockholders equity including treasury stock	223,504	260,593
Less treasury stock, at cost:
Common stock, 1,966,042 shares (2,009,566 shares at December 31, 2019)	12,884	13,266
Total stockholders' equity	210,620	247,327
Total Liabilities and Stockholders' equity	1,094,665	1,088,489
Series E Preferred Stock [Member]
Redeemable preferred stocks:
Redeemable preferred stock, value	252,898	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