Note 5 - Fair Value of Financial Instruments - Investment Securities With Unrealized Losses (Details) - USD ($)	Dec. 31, 2019	Mar. 31, 2019
Fair market value, less than 12 months	$ 4,169,606
Gross unrealized losses, less than 12 months	(9,538)
Fair market value, 12 months or greater		51,413,428
Gross unrealized losses, 12 months or greater		(421,798)
Total fair market value	4,169,606	51,413,428
Total gross unrealized losses	(9,538)	(421,798)
Corporate Bond Securities [Member]
Fair market value, less than 12 months	4,169,606
Gross unrealized losses, less than 12 months	(9,538)
Fair market value, 12 months or greater		51,413,428
Gross unrealized losses, 12 months or greater		(421,798)
Total fair market value	4,169,606	51,413,428
Total gross unrealized losses	$ (9,538)	$ (421,798)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
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