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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (5,044)	$ (8,169)	$ (7,344)	$ (3,737)
Other comprehensive income (loss) before reclassifications	(692)	(1,914)	1,628	(6,364)
Amounts reclassified from accumulated other comprehensive loss	(21)	23	(41)	41
Net-current period other comprehensive income (loss)	(713)	(1,891)	1,587	(6,323)
Ending balance	(5,757)	(10,060)	(5,757)	(10,060)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,151)	(5,346)	(5,323)	(1,165)
Other comprehensive income (loss) before reclassifications	(144)	(1,160)	2,028	(5,341)
Amounts reclassified from accumulated other comprehensive loss	0	0	0	0
Net-current period other comprehensive income (loss)	(144)	(1,160)	2,028	(5,341)
Ending balance	(3,295)	(6,506)	(3,295)	(6,506)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	842	(656)	862	(674)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive loss	(21)	23	(41)	41
Net-current period other comprehensive income (loss)	(21)	23	(41)	41
Ending balance	821	(633)	821	(633)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,735)	(2,167)	(2,883)	(1,898)
Other comprehensive income (loss) before reclassifications	(548)	(754)	(400)	(1,023)
Amounts reclassified from accumulated other comprehensive loss	0	0	0	0
Net-current period other comprehensive income (loss)	(548)	(754)	(400)	(1,023)
Ending balance	$ (3,283)	$ (2,921)	$ (3,283)	$ (2,921)