FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair value measurements
Available for sale securities	$ 164,183	$ 134,501
Trading securities	67,995	60,584
Fair value measured on a recurring basis
Fair value measurements
Cash and cash equivalents	119,145	126,145
Available for sale securities	164,183	134,501
Trading securities	67,995	60,584
Total assets measured at fair value	352,950	318,875
Fair value measured on a recurring basis \| Foreign currency forward contracts
Fair value measurements
Derivative instruments, net	(119)	(2,626)
Fair value measured on a recurring basis \| Commodity futures contracts
Fair value measurements
Derivative instruments, net	1,746	271
Fair value measured on a recurring basis \| Level 1
Fair value measurements
Cash and cash equivalents	119,145	126,145
Available for sale securities	2,419	2,430
Trading securities	67,995	60,584
Total assets measured at fair value	191,305	189,430
Fair value measured on a recurring basis \| Level 1 \| Commodity futures contracts
Fair value measurements
Derivative instruments, net	1,746	271
Fair value measured on a recurring basis \| Level 2
Fair value measurements
Available for sale securities	161,764	132,071
Total assets measured at fair value	161,645	129,445
Fair value measured on a recurring basis \| Level 2 \| Foreign currency forward contracts
Fair value measurements
Derivative instruments, net	$ (119)	$ (2,626)

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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