Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2011

Fair Value Disclosures [Abstract]

Financial assets and liabilities measured at fair value on recurring basis

	Fair Value at September 30, 2011
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	38,853	$	38,853	$	—	$	—
Short-term investments		1,160		1,160		—		—
Marketable equity securities		13,884		13,884		—		—
Restricted certificates of deposit		1,168		1,168		—		—
Put and call options		5,813		5,813		—		—
Silver ounces receivable from Mandalay		1,232		—		1,232		—
	$	62,110	$	60,878	$	1,232	$	—
Liabilities:
Royalty obligation embedded derivative	$	179,425	$	—	$	179,425	$	—
Put and call options		38,749		38,749		—		—
Other derivative instruments, net		6,445		—		6,445		—
	$	224,619	$	38,749	$	185,870	$	—

	Fair Value at December 31, 2010
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	11	$	11	$	—	$	—
Restricted certificates of deposit		2,965		2,965		—		—
Gold forward contract		425		425		—		—
Put and call options		5,403		5,403		—		—
Silver ounces receivable from Mandalay		1,594		—		1,594		—
Other derivative instruments, net		1,685		—		1,685		—
	$	12,083	$	8,804	$	3,279	$	—
Liabilities:
Gold lease facility	$	2,213	$	—	$	2,213	$	—
Royalty obligation embedded derivative		162,003		—		162,003		—
Put and call options		20,151		20,151		—		—
	$	184,367	$	20,151	$	164,216	$	—