Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Fair value measurements
Cash and cash equivalents	$ 57,216	$ 105,840	$ 76,210
Fair value measured on a recurring basis
Fair value measurements
Cash and cash equivalents	57,216	105,840	76,210
Available for sale securities	262,159	241,407	235,912
Trading securities	67,659	89,736	83,905
Total assets measured at fair value	386,637	437,533	396,883
Fair value measured on a recurring basis \| Foreign currency forward contracts
Fair value measurements
Derivative instruments, net	(366)	426	504
Fair value measured on a recurring basis \| Commodity futures contracts
Fair value measurements
Derivative instruments, net	(31)	124	352
Fair value measured on a recurring basis \| Level 1
Fair value measurements
Cash and cash equivalents	57,216	105,840	76,210
Available for sale securities	742	1,282	2,313
Trading securities	52,900	76,196	70,762
Total assets measured at fair value	110,827	183,442	149,637
Fair value measured on a recurring basis \| Level 1 \| Commodity futures contracts
Fair value measurements
Derivative instruments, net	(31)	124	352
Fair value measured on a recurring basis \| Level 2
Fair value measurements
Available for sale securities	261,417	240,125	233,599
Trading securities	14,759	13,540	13,143
Total assets measured at fair value	275,810	254,091	247,246
Fair value measured on a recurring basis \| Level 2 \| Foreign currency forward contracts
Fair value measurements
Derivative instruments, net	$ (366)	$ 426	$ 504

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Fair value of asset after deduction of liability.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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