Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 237,836	$ 190,984
Accounts receivable:
Trade	34,481	17,555
Other, net	17,263	7,466
Inventories:
Concentrates, doré, and stockpiled ore	23,425	15,073
Materials and supplies	20,214	13,564
Current deferred income taxes	36,141	29,398
Other current assets	20,526	8,858
Total current assets	389,886	282,898
Non-current investments	8,364	9,614
Non-current restricted cash and investments	5,378	871
Properties, plants, equipment and mineral interests, net	1,776,554	996,659
Non-current deferred income taxes	75,950	86,365
Other non-current assets and deferred charges	12,880	1,883
Total assets	2,269,012	1,378,290
Current liabilities:
Accounts payable and accrued liabilities	56,592	43,162
Accrued payroll and related benefits	18,128	10,760
Accrued taxes	3,729	12,321
Current portion of capital leases	7,398	5,564
Current portion of accrued reclamation and closure costs	74,481	19,845
Other current liabilities	17,576	3,335
Total current liabilities	177,904	94,987
Capital leases	12,603	11,935
Accrued reclamation and closure costs	49,862	93,370
Long-term debt	490,417	11,935
Non-current deferred tax liability	171,260
Other noncurrent liabilities	39,180	40,047
Total liabilities	941,226	240,339
Commitments and contingencies
Preferred stock, 5,000,000 shares authorized:
Series B preferred stock, $0.25 par value, 157,816 shares issued and outstanding, liquidation preference — $7,891	39	39
Common stock, $0.25 par value, authorized 500,000,000 shares; issued and outstanding 2013 — 342,638,214 shares and 2012 — 285,209,848 shares	85,890	71,499
Capital surplus	1,425,581	1,218,283
Accumulated deficit	(151,079)	(123,288)
Accumulated other comprehensive loss	(27,565)	(23,918)
Less treasury stock, at cost; 2013 — 921,721 and 2012 — 788,288 shares issued and held in treasury	(5,080)	(4,664)
Total shareholders’ equity	1,327,786	1,137,951
Total liabilities and shareholders’ equity	$ 2,269,012	$ 1,378,290