Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Fair Value Measurements
Cash and cash equivalents	$ 47,320	$ 53,270	$ 57,216
Fair value measured on a recurring basis
Fair Value Measurements
Cash and cash equivalents	47,320	53,270	57,216
Available for sale securities	251,531	272,448	262,159
Trading securities	79,754	71,208	67,659
Total assets measured at fair value	380,018	396,654	386,637
Fair value measured on a recurring basis \| Foreign currency derivatives.
Fair Value Measurements
Derivative instruments, net	(141)	(282)	(366)
Fair value measured on a recurring basis \| Commodity derivatives
Fair Value Measurements
Derivative instruments, net	1,554	10	(31)
Fair value measured on a recurring basis \| Level 1
Fair Value Measurements
Cash and cash equivalents	47,320	53,270	57,216
Available for sale securities	4,479	1,889	742
Trading securities	63,350	56,049	52,900
Total assets measured at fair value	116,703	111,218	110,827
Fair value measured on a recurring basis \| Level 1 \| Commodity derivatives
Fair Value Measurements
Derivative instruments, net	1,554	10	(31)
Fair value measured on a recurring basis \| Level 2
Fair Value Measurements
Available for sale securities	247,052	270,559	261,417
Trading securities	16,404	15,159	14,759
Total assets measured at fair value	263,315	285,436	275,810
Fair value measured on a recurring basis \| Level 2 \| Foreign currency derivatives.
Fair Value Measurements
Derivative instruments, net	$ (141)	$ (282)	$ (366)

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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