Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net income	$ 76,674	$ 38,928
Non-cash elements included in net income:
Depreciation, depletion and amortization	23,597	31,177
Gain on sale of investments	(611)	(588)
Loss on impairment of investments		739
Gain on disposition of properties, plants and equipment	(8)
Provision for reclamation and closure costs	556	2,502
Stock compensation	920	2,473
Deferred income taxes	38,319	268
Amortization of loan origination fees	332	320
(Gain) loss on derivative contracts	(9,198)	(2,202)
Other non-cash charges, net	391	328
Change in assets and liabilities:
Accounts receivable	(8,282)	4,023
Inventories	(2,856)	(3,207)
Other current and non-current assets	2,552	2,517
Accounts payable and accrued liabilities	12,818	11,455
Accrued payroll and related benefits	(445)	(7,332)
Accrued taxes	(6,364)	(1,256)
Accrued reclamation and closure costs and other non-current liabilities	(1,178)	(5,354)
Cash provided by operating activities	127,217	74,791
Investing activities:
Additions to properties, plants, equipment and mineral interests	(40,580)	(27,864)
Proceeds from sale of investments	1,366	1,138
Proceeds from disposition of properties, plants and equipment	113
Purchases of investments	(3,200)
Changes in restricted cash and investment balances	9,388	1,476
Net cash used in investing activities	(32,913)	(25,250)
Financing activities:
Proceeds from exercise of stock options and warrants	4,838	45,562
Acquisition of treasury shares	(469)	(693)
Dividends paid to preferred shareholders	(3,546)	(966)
Repayments of capital leases	(1,297)	(744)
Net cash (used) provided by financing activities	(474)	43,159
Change in cash and cash equivalents:
Net increase in cash and cash equivalents	93,830	92,700
Cash and cash equivalents at beginning of period	283,606	104,678
Cash and cash equivalents at end of period	377,436	197,378
Significant non-cash investing and financing activities:
Addition of capital lease obligations	2,543	563
Accounts payable change relating to capital additions	2,773	(1,437)
Preferred stock dividends paid in common stock		$ 19,620