Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Fair value measurements
Cash and cash equivalents	$ 26,047	$ 53,270	$ 46,628
Fair value measured on a recurring basis
Fair value measurements
Cash and cash equivalents	26,047	53,270	46,628
Available for sale securities	254,305	272,448	262,057
Trading securities	81,319	71,208	72,480
Total assets measured at fair value	360,973	396,654	381,430
Fair value measured on a recurring basis \| Foreign currency derivatives.
Fair value measurements
Derivative instruments, net	108	(282)	165
Fair value measured on a recurring basis \| Commodity derivatives
Fair value measurements
Derivative instruments, net	(806)	10	100
Fair value measured on a recurring basis \| Level 1
Fair value measurements
Cash and cash equivalents	26,047	53,270	46,628
Available for sale securities	4,510	1,889	748
Trading securities	65,065	56,049	56,964
Total assets measured at fair value	94,816	111,218	104,440
Fair value measured on a recurring basis \| Level 1 \| Commodity derivatives
Fair value measurements
Derivative instruments, net	(806)	10	100
Fair value measured on a recurring basis \| Level 2
Fair value measurements
Available for sale securities	249,795	270,559	261,309
Trading securities	16,254	15,159	15,516
Total assets measured at fair value	266,157	285,436	276,990
Fair value measured on a recurring basis \| Level 2 \| Foreign currency derivatives.
Fair value measurements
Derivative instruments, net	$ 108	$ (282)	$ 165

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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