COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (7,344)	$ (3,737)
Other comprehensive income (loss) before reclassifications	2,320	(4,450)
Amounts reclassified from accumulated other comprehensive loss	(20)	18
Net-current period other comprehensive income (loss)	2,300	(4,432)
Ending balance	(5,044)	(8,169)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(5,323)	(1,165)
Other comprehensive income (loss) before reclassifications	2,172	(4,181)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net-current period other comprehensive income (loss)	2,172	(4,181)
Ending balance	(3,151)	(5,346)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	862	(674)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	(20)	18
Net-current period other comprehensive income (loss)	(20)	18
Ending balance	842	(656)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,883)	(1,898)
Other comprehensive income (loss) before reclassifications	148	(269)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net-current period other comprehensive income (loss)	148	(269)
Ending balance	$ (2,735)	$ (2,167)