FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2013

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Financial assets and liabilities measured at fair value on recurring basis

The following table sets forth the Company’s financial assets and liabilities measured at fair value on a recurring basis (at least annually) by level within the fair value hierarchy. As required by accounting guidance, assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands):

	Fair Value at June 30, 2013
	Total		Level 1		Level 2		Level 3
Assets:
Marketable equity securities	$	16,008	$	16,008	$	—	$	—
Gold put and call options		2,358		—		2,358		—
	$	18,366	$	16,008	$	2,358	$	—
Liabilities:
Palmarejo royalty obligation embedded derivative	$	52,359	$	—	$	52,359	$	—
Rochester NSR royalty obligation		22,046		—		22,046		—
Other derivative instruments, net		2,554		—		2,554		—
	$	76,959	$	—	$	76,959	$	—

	Fair Value at December 31, 2012
	Total		Level 1		Level 2		Level 3
Assets:
Short term investments	$	999	$	999	$	—	$	—
Marketable securities		27,065		27,065		—		—
Other derivative instruments, net		943		—		943		—
	$	29,007	$	28,064	$	943	$	—
Liabilities:
Royalty obligation embedded derivative	$	145,098	$	—	$	145,098	$	—
Put and call options		9,299		—		9,299		—
	$	154,397	$	—	$	154,397	$	—

The following table sets forth the Company’s financial assets and liabilities measured at fair value on a recurring basis (at least annually) by level within the fair value hierarchy. As required by accounting guidance, assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands):

	Fair Value at December 31, 2012
	Total		Level 1		Level 2		Level 3
Assets:
Short-term investments	$	999	$	999	$	—	$	—
Marketable equity securities		27,065		27,065		—		—
Other derivative instruments, net		943		—		943		—
	$	29,007	$	28,064	$	943	$	—
Liabilities:
Royalty obligation embedded derivative	$	145,098	$	—	$	145,098	$	—
Put and call options		9,299		—		9,299		—
	$	154,397	$	—	$	154,397	$	—

	Fair Value at December 31, 2011
	Total		Level 1		Level 2		Level 3
Assets:
Short-term investments	$	20,254	$	20,254	$	—	$	—
Marketable equity securities		19,844		19,844		—		—
Put and call options		3,040		—		3,040		—
Silver ounces receivable from Mandalay		814		—		814		—
	$	43,952	$	40,098	$	3,854	$	—
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	$	—	$	184,304	$	—

Financial Assets and Liabilities not Measured at Fair Value

Financial assets and liabilities that are not measured at fair value at June 30, 2013 and December 31, 2012 are set forth below (in thousands):

	Fair Value at June 30, 2013
	Total		Level 1		Level 2		Level 3
Liabilities:
3.25% Convertible Senior Notes due 2028	$	5,153	$	5,153	$	—	$	—
7.875% Senior Notes due 2021	$	295,689	$	295,689	$	—	$	—
Palmarejo Gold Production Royalty Obligation	$	75,645	$	—	$	75,645	$	—
	Fair Value at December 31, 2012
	Total		Level 1		Level 2		Level 3
Liabilities:
3.25% Convertible Senior Notes due 2028	$	48,220	$	48,220	$	—	$	—
Palmarejo Gold Production Royalty Obligation	$	90,617	$	—	$	90,617	$	—

Financial assets and liabilities that are not measured at fair value at December 31, 2012 and December 31, 2011 are set forth in the following table (in thousands):

	Fair Value at December 31, 2012
	Total		Level 1		Level 2		Level 3
Liabilities:
3.25% Convertible Senior Notes	$	48,220	$	48,220	$	—	$	—
Palmarejo Gold Production Royalty Obligation	$	90,617	$	—	$	90,617	$	—

	Fair Value at December 31, 2011
	Total		Level 1		Level 2		Level 3
Liabilities:
3.25% Convertible Senior Notes	$	49,205	$	49,205	$	—	$	—
Palmarejo Gold Production Royalty Obligation	$	111,257	$	—	$	111,257	$	—