7. FINANCIAL INSTRUMENTS - Available-for-sale investments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020
Available-for-sale investments
Cost	$ 18,282
Total	18,459
Short-term investments
Available-for-sale investments
Cost	13,507	$ 14,989
Gross Unrealized Gains	89	73
Gross Unrealized Losses		(1)
Total	13,596	15,061
Short-term investments \| Agency bonds
Available-for-sale investments
Cost	1,495
Gross Unrealized Gains	10
Total	1,505
Short-term investments \| Supranational obligations
Available-for-sale investments
Cost	1,267	2,989
Gross Unrealized Gains	13	21
Total	1,280	3,010
Short-term investments \| Certificates of deposit
Available-for-sale investments
Cost	10,745	12,000
Gross Unrealized Gains	66	52
Gross Unrealized Losses		(1)
Total	10,811	12,051
Long-term investment
Available-for-sale investments
Cost	4,775	4,044
Gross Unrealized Gains	88	73
Total	4,863	4,117
Long-term investment \| Agency bonds
Available-for-sale investments
Cost	2,025	2,029
Gross Unrealized Gains	42	42
Total	2,067	2,071
Long-term investment \| Supranational obligations
Available-for-sale investments
Cost		1,270
Gross Unrealized Gains		13
Total		1,283
Long-term investment \| Certificates of deposit
Available-for-sale investments
Cost	2,750	745
Gross Unrealized Gains	46	18
Total	$ 2,796	$ 763

Amount, before tax, of unrealized gain 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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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
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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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