Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Fair value measurements
Cash and cash equivalents	$ 37,992	$ 53,270	$ 86,800
Fair value measured on a recurring basis
Fair value measurements
Cash and cash equivalents	37,992	53,270	86,800
Available for sale securities	262,729	272,448	250,845
Trading securities	76,039	71,208	84,662
Total assets measured at fair value	376,578	396,654	422,949
Fair value measured on a recurring basis \| Foreign currency derivatives.
Fair value measurements
Derivative instruments, net	(233)	(282)	400
Fair value measured on a recurring basis \| Commodity derivatives
Fair value measurements
Derivative instruments, net	51	10	242
Fair value measured on a recurring basis \| Level 1
Fair value measurements
Cash and cash equivalents	37,992	53,270	86,800
Available for sale securities	4,583	1,889	1,264
Trading securities	59,952	56,049	69,076
Total assets measured at fair value	102,578	111,218	157,382
Fair value measured on a recurring basis \| Level 1 \| Commodity derivatives
Fair value measurements
Derivative instruments, net	51	10	242
Fair value measured on a recurring basis \| Level 2
Fair value measurements
Available for sale securities	258,146	270,559	249,581
Trading securities	16,087	15,159	15,586
Total assets measured at fair value	274,000	285,436	265,567
Fair value measured on a recurring basis \| Level 2 \| Foreign currency derivatives.
Fair value measurements
Derivative instruments, net	$ (233)	$ (282)	$ 400

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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