7. FINANCIAL INSTRUMENTS - Unrealized losses and fair value (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Fair Value
Less Than 12 Months, Fair Value	$ 4,317	$ 9,590
12 Months or Greater, Fair Value	1,733	246
Total, Fair Value	6,050	9,836
Unrealized Loss
Less Than 12 Months, Unrealized Loss	(88)	(76)
12 Months or Greater, Unrealized Loss	(16)	(3)
Total, Unrealized Loss	(104)	(79)
Certificates of Deposit
Fair Value
Less Than 12 Months, Fair Value	1,720	4,974
12 Months or Greater, Fair Value	1,733	246
Total, Fair Value	3,453	5,220
Unrealized Loss
Less Than 12 Months, Unrealized Loss	(30)	(26)
12 Months or Greater, Unrealized Loss	(16)	(3)
Total, Unrealized Loss	(46)	(29)
Bonds
Fair Value
Less Than 12 Months, Fair Value	1,969	2,982
Total, Fair Value	1,969	2,982
Unrealized Loss
Less Than 12 Months, Unrealized Loss	(33)	(26)
Total, Unrealized Loss	(33)	(26)
Supranational obligations
Fair Value
Less Than 12 Months, Fair Value	628	1,634
Total, Fair Value	628	1,634
Unrealized Loss
Less Than 12 Months, Unrealized Loss	(25)	(24)
Total, Unrealized Loss	$ (25)	$ (24)