7. FINANCIAL INSTRUMENTS - Available-for-sale investments (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022
Available-for-sale investments
Cost	$ 8,910
Total	8,803
Short-term Investments
Available-for-sale investments
Cost	8,008	$ 7,018
Gross Unrealized Losses	(80)	(26)
Total	7,928	6,992
Short-term investments, Certificates of deposit
Available-for-sale investments
Cost	5,000	4,000
Gross Unrealized Losses	(43)	(11)
Total	4,957	3,989
Short-term investments, Supranational obligations
Available-for-sale investments
Cost	1,003	1,007
Gross Unrealized Losses	(4)	(7)
Total	999	1,000
Short-term investments, Agency bonds
Available-for-sale investments
Cost	2,005	2,011
Gross Unrealized Losses	(33)	(8)
Total	1,972	2,003
Other Long-term Investments
Available-for-sale investments
Cost	902	3,398
Gross Unrealized Losses	(27)	(53)
Total	875	3,345
Long-term investments, Certificates of deposit
Available-for-sale investments
Cost	250	1,750
Gross Unrealized Losses	(7)	(18)
Total	243	1,732
Long-term investments, Supranational obligations
Available-for-sale investments
Cost	652	651
Gross Unrealized Losses	(20)	(17)
Total	$ 632	634
Long-term investments, Agency bonds
Available-for-sale investments
Cost		997
Gross Unrealized Losses		(18)
Total		$ 979

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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