CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 75,892	$ 65,308	$ 58,974
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation	17,668	17,570	18,184
Deferred income taxes	1,535	(1,263)	(279)
Amortization of marketable security premiums	5,531	3,837	1,404
Changes in operating assets and liabilities:
Accounts receivable	(3,073)	(14,130)	3,483
Other receivables	(1,020)	(706)	636
Inventories	(28,415)	3,940	(770)
Prepaid expenses and other assets	49	2,622	2,961
Accounts payable and accrued liabilities	10,329	10,010	3,849
Income taxes payable	(4,565)	(1,296)	3,012
Postretirement health care benefits	(804)	(1,281)	(1,041)
Deferred compensation and other liabilities	(1,076)	687	(15,703)
Net cash provided by operating activities	72,051	85,298	74,710
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(23,356)	(31,426)	(17,970)
Repayment of premiums on split dollar life insurance policies		2,514	23,527
Purchases of trading securities	(1,543)	(2,668)	(3,183)
Sales of trading securities	2,806	968	18,058
Purchase of available for sale securities	(96,114)	(108,576)	(109,816)
Sale and maturity of available for sale securities	49,618	47,289	98,885
Net cash (used in) provided by investing activities	(68,589)	(91,899)	9,501
CASH FLOWS FROM FINANCING ACTIVITIES:
Shares purchased and retired	(31,910)	(30,184)	(32,055)
Dividends paid in cash	(24,629)	(24,136)	(23,810)
Proceeds from bank loans	3,989	3,792	3,902
Repayment of bank loans	(3,850)	(3,618)	(3,883)
Net cash used in financing activities	(56,400)	(54,146)	(55,846)
Effect of exchange rate changes on cash	347	(283)	(449)
Increase (decrease) in cash and cash equivalents	(52,591)	(61,030)	27,916
Cash, cash equivalents and restricted cash at beginning of year	106,226	167,256	139,340
Cash, cash equivalents and restricted cash at end of year	53,635	106,226	167,256
Supplemental cash flow information:
Income taxes paid	23,884	22,855	14,503
Interest paid	78	6	57
Stock dividend issued	$ 70,242	$ 64,667	$ 63,402