Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Net income	$ 15,096	$ 76,674
Non-cash elements included in net income:
Depreciation, depletion and amortization	22,799	23,597
Gain on sale of investments		(611)
(Gain) loss on disposition of properties, plants, equipment, and mineral interests	660	(8)
Provision for reclamation and closure costs	2,908	556
Stock compensation	1,495	920
Deferred income taxes	3,697	38,319
Amortization of loan origination fees	201	332
(Gain) loss on derivative contracts	9,376	(9,198)
Other non-cash charges, net	604	391
Change in assets and liabilities:
Accounts receivable	(16,838)	(8,282)
Inventories	3,013	(2,856)
Other current and non-current assets	1,756	2,552
Accounts payable and accrued liabilities	389	12,818
Accrued payroll and related benefits	(3,696)	(445)
Accrued taxes	(6,618)	(6,364)
Accrued reclamation and closure costs and other non-current liabilities	(3,602)	(1,178)
Cash provided by operating activities	31,240	127,217
Investing activities:
Additions to properties, plants, equipment and mineral interests	(51,535)	(40,580)
Proceeds from sale of investments		1,366
Proceeds from disposition of properties, plants and equipment	116	113
Purchases of investments		(3,200)
Changes in restricted cash and investment balances		9,388
Net cash used in investing activities	(51,419)	(32,913)
Financing activities:
Proceeds from exercise of stock options and warrants		4,838
Acquisition of treasury shares	(203)	(469)
Dividends paid to common shareholders	(9,986)
Dividends paid to preferred shareholders	(276)	(3,546)
Repayments of capital leases	(2,492)	(1,297)
Net cash used in financing activities	(12,957)	(474)
Change in cash and cash equivalents:
Net increase (decrease) in cash and cash equivalents	(33,136)	93,830
Cash and cash equivalents at beginning of period	266,463	283,606
Cash and cash equivalents at end of period	233,327	377,436
Significant non-cash investing and financing activities:
Addition of capital lease obligations	5,828	2,543
Accounts payable change relating to capital additions	$ (3,632)	$ 2,773