FINANCIAL INSTRUMENTS - Cash and Financial Assets That are Measured at Fair Value on a Recurring Basis for Each of the Hierarchy Levels (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	$ 122,029		$ 109,464
Unrealized Gains	7		21
Accrued Interest	24		59
Estimated Fair Value	122,060		109,544
Cash & Cash Equivalents	118,003		104,183
Investment Securities	4,057		5,361
Cash
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	107,342		94,824
Estimated Fair Value	107,342		94,824
Cash & Cash Equivalents	107,342		94,824
Level 1:
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	12,062		10,760
Unrealized Gains	5		12
Accrued Interest	8
Estimated Fair Value	12,075		10,772
Cash & Cash Equivalents	10,661		9,359
Investment Securities	1,414		1,413
Level 1: | Money market accounts
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	10,661		9,359
Estimated Fair Value	10,661		9,359
Cash & Cash Equivalents	10,661		9,359
Level 1: | Government & agency securities
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	1,401		1,401
Unrealized Gains	5		12
Accrued Interest	8
Estimated Fair Value	1,414		1,413
Investment Securities	1,414		1,413
Level 2: | Municipal bonds
Cash And Cash Equivalents And Marketable securities [Line Items]
Cost	2,625		3,880
Unrealized Gains	2	$ 9
Accrued Interest	16		59
Estimated Fair Value	2,643		3,948
Investment Securities	$ 2,643		$ 3,948