Note 5 - Gross Unrealized Losses and Fair Value of Investments (Details) - USD ($)
|
3 Months Ended |
6 Months Ended |
12 Months Ended |
Sep. 30, 2015 |
Sep. 30, 2015 |
Mar. 31, 2015 |
| Corporate Bond Securities [Member] |
|
|
|
| Fair market value less than 12 months |
$ 8,834,101
|
$ 8,834,101
|
$ 3,015,900
|
| Gross unrealized losses less than 12 months |
|
(9,840)
|
(163)
|
| Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |
2,597,444
|
2,597,444
|
2,590,240
|
| Gross unrealized losses greater than 12 months |
|
(7,775)
|
(16,208)
|
| Total Fair Market Value |
11,431,545
|
11,431,545
|
5,606,140
|
| Total Gross Unrealized Losses |
$ (17,615)
|
$ (17,615)
|
$ (16,371)
|
| Municipal Bonds [Member] |
|
|
|
| Fair market value less than 12 months |
|
|
|
| Gross unrealized losses less than 12 months |
|
|
|
| Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |
|
|
|
| Gross unrealized losses greater than 12 months |
|
|
|
| Total Fair Market Value |
|
|
|
| Total Gross Unrealized Losses |
|
|
|
| Fair market value less than 12 months |
$ 8,834,101
|
$ 8,834,101
|
$ 3,015,900
|
| Gross unrealized losses less than 12 months |
|
(9,840)
|
(163)
|
| Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |
2,595,544
|
2,595,544
|
2,590,240
|
| Gross unrealized losses greater than 12 months |
|
(7,775)
|
(16,208)
|
| Total Fair Market Value |
$ 11,431,545
|
11,431,545
|
5,606,140
|
| Total Gross Unrealized Losses |
|
$ (17,615)
|
$ (16,371)
|