Note 5 - Investment Securities Available for Sale - Amortized Cost and Fair Value of Securities (Details) - USD ($)	Jun. 30, 2017	Mar. 31, 2017
Gross unrealized gains	$ 105,205	$ 87,275
Gross unrealized losses	1,742,889	2,274,302
Fair value	98,613,783	102,429,128
Amortized cost	100,251,467	104,616,155
Collateralized Mortgage Backed Securities [Member]
Gross unrealized gains	74,001	65,094
Gross unrealized losses	1,030,266	1,226,935
Fair value	76,721,809	80,832,464
Amortized cost	77,678,074	81,994,305
US Government Agencies Debt Securities [Member]
Gross unrealized gains	310	323
Gross unrealized losses	13,142	13,393
Fair value	3,508,628	3,512,303
Amortized cost	3,521,460	3,525,373
Municipal Bonds [Member]
Gross unrealized gains	30,894	21,858
Gross unrealized losses	618,977	950,496
Fair value	16,463,850	16,167,839
Amortized cost	17,051,933	17,096,477
Corporate Bond Securities [Member]
Gross unrealized gains
Gross unrealized losses	80,504	83,478
Fair value	1,919,496	1,916,522
Amortized cost	$ 2,000,000	$ 2,000,000

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
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-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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