Note 5 - Marketable Securities (Tables)

6 Months Ended

Sep. 30, 2015

Notes Tables

Marketable Securities [Table Text Block]

Total		<1 Year		1–3 Years		3–5 Years
$	83,956,776	$	23,175,666	$	39,590,273	$	21,190,837

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

	As of September 30, 2015									As of March 31, 2015
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value		Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Corporate bonds	$	81,960,402	$	645,841	$	(17,615	)	$	82,588,628	$	88,456,886	$	1,185,469	$	(16,371	)	$	89,625,984
Municipal bonds		1,364,084		4,064		-			1,368,148		1,383,839		3,272		-			1,387,111
Total	$	83,324,486	$	649,905	$	(17,615	)	$	83,956,776	$	89,840,725	$	1,188,741	$	(16,371	)	$	91,013,095

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less Than 12 Months					12 Months or Greater					Total
	Fair Market Value		Gross Unrealized Losses			Fair Market Value		Gross Unrealized Losses			Fair Market Value		Gross Unrealized Losses
As of September 30, 2015
Corporate bonds	$	8,834,101	$	(9,840	)	$	2,597,444	$	(7,775	)	$	11,431,545	$	(17,615	)
Municipal bonds		-		-			-		-			-		-
Total	$	8,834,101	$	(9,840	)	$	2,595,544	$	(7,775	)	$	11,431,545	$	(17,615	)
As of March 31, 2015
Corporate bonds	$	3,015,900	$	(163	)	$	2,590,240	$	(16,208	)	$	5,606,140	$	(16,371	)
Municipal bonds		-		-			-		-			-		-
Total	$	3,015,900	$	(163	)	$	2,590,240	$	(16,208	)	$	5,606,140	$	(16,371	)