Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net income	$ 14,954	$ 151,164	$ 48,983
Depreciation, depletion and amortization	50,113	47,348	60,235
Net gain on sale of investments		(611)	(588)
Loss on impairment of investments	1,171	140	739
Loss on disposition of properties, plants, equipment and mineral interests	275		80
Provision for reclamation and closure costs	1,106	7,004	196,262
Deferred income taxes	546	76,944	(141,707)
Stock compensation	3,101	2,073	3,446
Amortization of loan origination fees	460	598	621
Amortization of intangible asset			1,380
(Gain) loss on derivative contracts	29,627	(53,545)	20,795
Other non-cash items	1,765	1,209	(495)
Accounts receivable	(4,713)	16,531	(9,404)
Inventories	(2,442)	(7,064)	2,335
Other current and non-current assets	610	2,164	3,279
Accounts payable and accrued liabilities	4,927	1,466	10,896
Accrued payroll and related benefits	(2,118)	2,090	(3,376)
Accrued taxes	1,967	(5,688)	9,802
Accrued reclamation and closure costs and other non-current liabilities	(32,333)	(171,932)	(5,474)
Net cash provided by operating activities	69,016	69,891	197,809
Investing activities:
Additions to properties, plants, equipment and mineral interests	(113,096)	(87,546)	(67,414)
Proceeds from sale of investments		1,366	1,138
Proceeds from disposition of properties, plants and equipment	886	113	29
Redemptions of restricted cash and investment balances		9,448	1,459
Increases in restricted cash and investment balances	(5)	(3,200)
Purchases of investments	(5,823)
Net cash used by investing activities	(118,038)	(79,819)	(64,788)
Financing activities:
Proceeds from exercise of warrants and stock options	700	5,786	53,093
Dividends paid to common shareholders	(17,121)	(5,592)
Dividend paid to preferred shareholders	(552)	(3,822)	(4,513)
Loan origination fees paid	(750)	(180)	(200)
Acquisition of treasury shares	(2,144)	(469)	(693)
Repayments of capital leases	(5,890)	(2,938)	(1,780)
Net cash provided by (used in) financing activities	(26,457)	(7,215)	45,907
Net increase (decrease) in cash and cash equivalents	(75,479)	(17,143)	178,928
Cash and cash equivalents at beginning of year	266,463	283,606	104,678
Cash and cash equivalents at end of year	190,984	266,463	283,606
Supplemental disclosure of cash flow information:
Interest	1,968	1,683	584
Income tax payments	3	17,874	11,075
Stock issued for acquisition of assets		33,831
Capital leases acquired	13,119	6,935	3,212
Accounts payable change relating to capital additions	3,727	8,687	3,488
Preferred stock dividends paid in common stock			$ 22,891