Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 266,463	$ 283,606
Investments		1,474
Accounts receivable:
Trade	10,996	36,295
Other, net	9,313	545
Concentrates, doré, stockpiled ore, and metals in transit and in-process	13,692	8,886
Materials and supplies	12,503	10,245
Current deferred income taxes	27,810	87,287
Other current assets	21,967	3,683
Total current assets	362,744	432,021
Non-current investments	3,923	1,194
Non-current restricted cash and investments	866	10,314
Properties, plants, equipment and mineral interests, net	923,212	833,288
Non-current deferred income taxes	88,028	100,072
Other non-current assets	17,317	5,604
Total assets	1,396,090	1,382,493
Current liabilities:
Accounts payable and accrued liabilities	37,831	31,725
Accrued payroll and related benefits	12,878	10,789
Accrued taxes	10,354	16,042
Current portion of capital leases	4,005	2,481
Current portion of accrued reclamation and closure costs	42,248	175,484
Current derivative contract liabilities		20,016
Total current liabilities	107,316	256,537
Long-term capital leases	6,265	3,792
Accrued reclamation and closure costs	111,563	143,313
Other non-current liabilities	30,833	16,598
Total liabilities	255,977	420,240
Preferred stock, 5,000,000 shares authorized:
Common stock, $0.25 par value, authorized 500,000,000 shares; issued and outstanding 2011 — 285,289,924 shares and 2010 — 258,485,666 shares	71,420	64,704
Capital surplus	1,215,229	1,179,751
Accumulated deficit	(120,557)	(265,577)
Accumulated other comprehensive loss, net	(23,498)	(15,117)
Less treasury stock, at cost; 2011 — 392,645 shares and 2010 — 335,957 shares	(2,520)	(2,051)
Total shareholders’ equity	1,140,113	962,253
Total liabilities and shareholders’ equity	1,396,090	1,382,493
Series B Preferred Stock [Member]
Preferred stock, 5,000,000 shares authorized:
Preferred stock, value issued	39	39
Mandatory Convertible Preferred Stock [Member]
Preferred stock, 5,000,000 shares authorized:
Preferred stock, value issued		$ 504