Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Sales of products	$ 117,860	$ 88,631	$ 254,224	$ 168,506
Cost of sales and other direct production costs	38,865	35,545	83,394	71,815
Depreciation, depletion and amortization	11,204	15,020	23,466	31,089
[CostOfRevenue]	50,069	50,565	106,860	102,904
Gross profit	67,791	38,066	147,364	65,602
Other operating expenses:
General and administrative	4,550	4,664	9,249	8,777
Exploration	5,839	5,820	9,140	9,249
Other operating expense	2,270	1,601	4,087	2,565
Provision for closed operations and environmental matters	1,341	1,389	2,362	4,765
[DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax]	14,000	13,474	24,838	25,356
Income from operations	53,791	24,592	122,526	40,246
Other income (expense):
Gain (loss) on sale or impairment of investments		(739)	611	(151)
Gain (loss) on derivative contracts	559	1,999	(1,475)	1,999
Interest and other income	105	16	123	67
Interest expense	(1,496)	(529)	(1,973)	(1,207)
[NonoperatingIncomeExpense]	(832)	747	(2,714)	708
Income before income taxes	52,959	25,339	119,812	40,954
Income tax provision	(19,642)	(8,255)	(43,138)	(2,026)
Net income	33,317	17,084	76,674	38,928
Reclassification of net (gain) loss on sale or impairment of marketable securities included in net income		739	(611)	739
Unrealized holding losses on investments	(1,082)	(510)	(115)	(1,488)
Comprehensive income	32,235	17,313	75,948	38,179
Basic income per common share after preferred dividends (in Dollars per share)	$ 0.12	$ 0.06	$ 0.27	$ 0.13
Diluted income per common share after preferred dividends (in Dollars per share)	$ 0.11	$ 0.05	$ 0.26	$ 0.12
Weighted average number of common shares outstanding - basic (in Shares)	279,347	248,549	278,901	245,371
Weighted average number of common shares outstanding - diluted (in Shares)	295,756	266,374	296,020	263,868
Preferred stock dividends	(138)	(3,409)	(276)	(6,817)
Income applicable to common shareholders	$ 33,179	$ 13,675	$ 76,398	$ 32,111