Condensed Consolidated Statements of Operations (Loss) (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Sales of metal	$ 200,825	$ 230,593	$ 577,147	$ 689,563
Production costs applicable to sales	(131,728)	(124,967)	(363,437)	(349,344)
Depreciation, Depletion and Amortization	(60,874)	(52,844)	(168,963)	(166,460)
Gross profit	8,223	52,782	44,747	173,759
COSTS AND EXPENSES
General and administrative	16,240	10,266	41,492	26,456
Exploration	3,305	6,957	16,920	19,829
Litigation settlement	0	0	32,046	0
Loss on impairment	0	1,293	205	6,106
Pre-development, care, maintenance and other	3,955	277	9,414	1,618
Total costs and expenses	23,500	18,793	100,077	54,009
OPERATING INCOME (LOSS)	(15,277)	33,989	(55,330)	119,750
OTHER INCOME AND EXPENSE
Fair value adjustments, net	(20,646)	(37,648)	63,905	(44,722)
Other than temporary impairment of marketable securities	(870)	(605)	(18,097)	(605)
Interest income and other, net	(1,791)	13,269	2,484	15,055
Interest expense, net of capitalized interest	(9,662)	(7,351)	(30,324)	(21,578)
Total other income and expense	(32,969)	(32,335)	17,968	(51,850)
Income (loss) before income taxes	(48,246)	1,654	(37,362)	67,900
Income tax provision	1,981	(17,475)	(31,673)	(56,773)
NET INCOME (LOSS)	$ (46,265)	$ (15,821)	$ (69,035)	$ 11,127
Basic income per share:
Net income	$ (0.46)	$ (0.18)	$ (0.71)	$ 0.12
Diluted income per share:
Net income	$ (0.46)	$ (0.18)	$ (0.71)	$ 0.12