CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 86,808	$ 91,886	$ 75,892
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation	18,176	18,243	17,668
Deferred income taxes	7,758	(913)	1,535
Amortization of marketable security premiums	1,829	3,946	5,531
Changes in operating assets and liabilities:
Accounts receivable	10,226	4,891	(3,073)
Other receivables	1,444	(4,574)	(1,020)
Inventories	15,790	(9,601)	(28,415)
Prepaid expenses and other assets	2,559	(15,856)	49
Accounts payable and accrued liabilities	635	(3,570)	10,329
Income taxes payable	(7,664)	9,583	(4,565)
Postretirement health care benefits	(253)	(649)	(804)
Deferred compensation and other liabilities	1,581	1,225	(1,076)
Net cash provided by operating activities	138,889	94,611	72,051
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(17,997)	(26,796)	(23,356)
Purchases of trading securities	(2,257)	(1,875)	(1,543)
Sales of trading securities	1,314	774	2,806
Purchase of available for sale securities	(108,728)	(92,431)	(96,114)
Sale and maturity of available for sale securities	91,826	106,128	49,618
Net cash used in investing activities	(35,842)	(14,200)	(68,589)
CASH FLOWS FROM FINANCING ACTIVITIES:
Shares purchased and retired	(13,534)	(33,114)	(31,910)
Dividends paid in cash	(25,515)	(25,076)	(24,629)
Proceeds from bank loans	3,828	3,499	3,989
Repayment of bank loans	(3,928)	(3,489)	(3,850)
Net cash used in financing activities	(39,149)	(58,180)	(56,400)
Effect of exchange rate changes on cash	(995)	424	347
Increase (decrease) in cash and cash equivalents	62,903	22,655	(52,591)
Cash, cash equivalents and restricted cash at beginning of year	76,290	53,635	106,226
Cash, cash equivalents and restricted cash at end of year	139,193	76,290	53,635
Supplemental cash flow information:
Income taxes paid	38,165	19,583	23,884
Interest paid	268	258	78
Stock dividend issued	$ 66,243	$ 86,433	$ 70,242