FAIR VALUE MEASUREMENT (Tables)

6 Months Ended

Jun. 30, 2013

FAIR VALUE MEASUREMENT

Financial assets and liabilities measured at fair value within the fair value hierarchy

• The following table summarizes the Company's financial assets and liabilities measured at fair value as at June 30, 2013 within the fair value hierarchy:

	Level 1		Level 2		Level 3		Total
Financial assets:
Trade receivables(i)	$	—	$	60,001	$	—	$	60,001
Available-for-sale securities(ii)		68,805		—		—		68,805
Fair value of derivative financial instruments(iii)		—		7,135		—		7,135
	$	68,805	$	67,136	$	—	$	135,941
Financial liabilities:
Fair value of derivative financial instruments(iii)	$	—	$	1,968	$	—	$	1,968

• The following table details the Company's financial assets and liabilities measured at fair value as at December 31, 2012 within the fair value hierarchy:

	Level 1		Level 2		Level 3		Total
Financial assets:
Trade receivables(i)	$	—	$	67,750	$	—	$	67,750
Available-for-sale securities(ii)		44,719		—		—		44,719
Fair value of derivative financial instruments(iii)		—		2,112		—		2,112
	$	44,719	$	69,862	$	—	$	114,581
Financial liabilities:
Fair value of derivative financial instruments(iii)	$	—	$	277	$	—	$	277

• (i)

  Trade receivables from provisional invoices for concentrate sales are valued using quoted forward rates derived from observable market data based on the month of expected settlement (classified within Level 2 of the fair value hierarchy).
  
  

  (ii)

  Available-for-sale securities are recorded at fair value using quoted market prices (classified within Level 1 of the fair value hierarchy).
  
  

  (iii)

  Derivative financial instruments are recorded at fair value using external broker-dealer quotations (classified within Level 2 of the fair value hierarchy).