Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2011

Fair Value Measurements [Abstract]

Financial assets and liabilities measured at fair value on recurring basis

	Fair Value at December 31, 2011
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	44,708	$	44,708	$	—	$	—
Short term investments		20,254		20,254		—		—
Marketable securities		19,844		19,844		—		—
Restricted certificates of deposit		548		548		—		—
Put and call options		3,040		5,920		—		—
Silver ounces receivable from Mandalay		814		—		814		—
	$	89,208	$	91,274	$	814	$	—
Liabilities:
Royalty obligation embedded derivative	$	159,400	$	—	$	159,400	$	—
Put and call options		20,892		20,892		—		—
Other derivative instruments, net		4,012		—		4,012		—
	$	184,304	$	20,892	$	163,412	$	—

	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 ounce 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	$	—