COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS (Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (8,169)	$ (2,836)	$ (3,737)	$ (2,163)
Other comprehensive income (loss) before reclassifications	(1,914)	(371)	(6,364)	(969)
Amounts reclassified from accumulated other comprehensive loss	23	52	41	(23)
Net-current period other comprehensive income (loss)	(1,891)	(319)	(6,323)	(992)
Ending balance	(10,060)	(3,155)	(10,060)	(3,155)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(5,346)	310	(1,165)	890
Other comprehensive income (loss) before reclassifications	(1,160)	(331)	(5,341)	(911)
Amounts reclassified from accumulated other comprehensive loss	0	0	0	0
Net-current period other comprehensive income (loss)	(1,160)	(331)	(5,341)	(911)
Ending balance	(6,506)	(21)	(6,506)	(21)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(656)	(1,716)	(674)	(1,641)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive loss	23	52	41	(23)
Net-current period other comprehensive income (loss)	23	52	41	(23)
Ending balance	(633)	(1,664)	(633)	(1,664)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,167)	(1,430)	(1,898)	(1,412)
Other comprehensive income (loss) before reclassifications	(754)	(40)	(1,023)	(58)
Amounts reclassified from accumulated other comprehensive loss	0	0	0	0
Net-current period other comprehensive income (loss)	(754)	(40)	(1,023)	(58)
Ending balance	$ (2,921)	$ (1,470)	$ (2,921)	$ (1,470)