CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 23,958	$ 186,811
Restricted cash		365
Short-term investments	15,000	14,500
Accounts receivable, net	90,064	88,074
Inventories:
Finished goods	24,170	28,218
Work in progress	2,743	2,763
Raw materials	26,782	25,605
Total inventories	53,695	56,586
Supplies, prepaid items and other:
Prepaid insurance	2,611	13,752
Precious metals	14,398	12,838
Supplies	17,220	15,927
Prepaid and refundable income taxes	8,709	7,387
Other	4,175	5,438
Total supplies, prepaid items and other	47,113	55,342
Deferred income taxes	20,385	17,204
Total current assets	250,215	418,882
Property, plant and equipment, net	874,575	619,205
Other assets:
Noncurrent restricted cash and cash equivalents		45,969
Noncurrent restricted investments		25,000
Intangible and other, net	32,204	27,949
Total other assets	32,204	98,918
Total assets	1,156,994	1,137,005
Current liabilities:
Accounts payable	110,950	81,456
Short-term financing	1,204	11,955
Accrued and other liabilities	46,317	51,166
Current portion of long-term debt	23,849	10,680
Total current liabilities	182,320	155,257
Long-term debt	472,599	446,638
Noncurrent accrued and other liabilities	17,863	17,934
Deferred income taxes	$ 73,182	$ 83,128
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $.10 par value; 75,000,000 shares authorized, 27,131,724 shares issued (26,968,212 shares at December 31, 2014)	$ 2,713	$ 2,697
Capital in excess of par value	174,500	170,537
Retained earnings	259,191	286,188
Stockholders equity including treasury stock	439,404	462,422
Less treasury stock, at cost:
Common stock, 4,320,462 shares	28,374	28,374
Total stockholders' equity	411,030	434,048
Total Liabilities and Stockholders' equity	1,156,994	1,137,005
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