COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (3,737)	$ (2,163)	$ (3,130)
Other comprehensive income (loss) before reclassifications	(3,684)	(1,741)	760
Amounts reclassified from accumulated other comprehensive loss	77	167	207
Other comprehensive loss	(3,607)	(1,574)	967
Ending balance	(7,344)	(3,737)	(2,163)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,165)	890	583
Other comprehensive income (loss) before reclassifications	(4,158)	(2,055)	307
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive loss	(4,158)	(2,055)	307
Ending balance	(5,323)	(1,165)	890
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(674)	(1,641)	(2,484)
Other comprehensive income (loss) before reclassifications	1,459	800	636
Amounts reclassified from accumulated other comprehensive loss	77	167	207
Other comprehensive loss	1,536	967	843
Ending balance	862	(674)	(1,641)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,898)	(1,412)	(1,229)
Other comprehensive income (loss) before reclassifications	(985)	(486)	(183)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive loss	(985)	(486)	(183)
Ending balance	$ (2,883)	$ (1,898)	$ (1,412)