Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 133,773,000	$ 124,929,000
Restricted cash	54,000	31,000
Short-term investments		10,005,000
Accounts receivable, net	110,999,000	87,351,000
Inventories:
Finished goods	33,994,000	29,009,000
Work in progress	4,174,000	4,855,000
Raw materials	27,045,000	25,642,000
Total inventories	65,213,000	59,506,000
Supplies, prepaid items and other:
Prepaid insurance	1,342,000	5,953,000
Precious metals	14,708,000	17,777,000
Supplies	9,602,000	7,513,000
Fair value of derivatives and other	332,000	53,000
Prepaid income taxes	5,279,000	8,679,000
Other	2,125,000	2,034,000
Total supplies, prepaid items and other	33,388,000	42,009,000
Deferred income taxes	5,281,000	4,275,000
Total current assets	348,708,000	328,106,000
Property, plant and equipment, net	202,173,000	164,547,000
Other assets:
Investment in affiliate	2,135,000	2,910,000
Goodwill	1,724,000	1,724,000
Other, net	6,429,000	4,722,000
Total other assets	10,288,000	9,356,000
Total assets	561,169,000	502,009,000
Current liabilities:
Accounts payable	64,899,000	57,891,000
Short-term financing	569,000	5,646,000
Accrued and other liabilities	38,762,000	28,677,000
Current portion of long-term debt	4,781,000	4,935,000
Total current liabilities	109,011,000	97,149,000
Long-term debt	68,849,000	74,525,000
Noncurrent accrued and other liabilities	16,531,000	15,239,000
Deferred income taxes	24,625,000	21,826,000
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $.10 par value; 75,000,000 shares authorized, 26,705,530 shares issued (26,638,285 at December 31, 2011)	2,670,000	2,664,000
Capital in excess of par value	164,225,000	162,092,000
Retained earnings	200,632,000	153,888,000
Stockholders equity including treasury stock	370,527,000	321,644,000
Less treasury stock at cost:
Common stock, 4,320,462 shares	28,374,000	28,374,000
Total stockholders' equity	342,153,000	293,270,000
Total Liabilities and Stockholders' equity	561,169,000	502,009,000
Series B preferred stock
Stockholders' equity:
Convertible preferred stock	2,000,000	2,000,000
Series D preferred stock
Stockholders' equity:
Convertible preferred stock	$ 1,000,000	$ 1,000,000