COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (7,344)	$ (3,737)	$ (2,163)
Other comprehensive income (loss) before reclassifications	5,970	(3,684)	(1,741)
Amounts reclassified from accumulated other comprehensive loss	(88)	77	167
Other comprehensive income (loss)	5,882	(3,607)	(1,574)
Ending balance	(1,462)	(7,344)	(3,737)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(5,323)	(1,165)	890
Other comprehensive income (loss) before reclassifications	5,579	(4,158)	(2,055)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive income (loss)	5,579	(4,158)	(2,055)
Ending balance	256	(5,323)	(1,165)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	862	(674)	(1,641)
Other comprehensive income (loss) before reclassifications	811	1,459	800
Amounts reclassified from accumulated other comprehensive loss	(88)	77	167
Other comprehensive income (loss)	723	1,536	967
Ending balance	1,585	862	(674)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,883)	(1,898)	(1,412)
Other comprehensive income (loss) before reclassifications	(420)	(985)	(486)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive income (loss)	(420)	(985)	(486)
Ending balance	$ (3,303)	$ (2,883)	$ (1,898)