Note 9 - Lines of Credit and Federal Home Loan Bank Advances (Details Textual) - USD ($)	6 Months Ended
Sep. 30, 2018	Mar. 31, 2018
Federal Home Loan Bank Advances Total Funding Available As A Percent Of Total Assets	25.00%
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	$ 76,700,000	$ 68,300,000
Loans Pledged as Collateral	117,500,000	127,100,000
Derivative, Notional Amount	11,550,000
Secured Debt [Member]
Line of Credit Facility, Maximum Borrowing Capacity	5,000,000
Unsecured Debt [Member]
Line of Credit Facility, Maximum Borrowing Capacity	1,000,000
Long-term Line of Credit, Total	0	$ 0
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 3 [Member] \| Borrowing One [Member]
Derivative, Notional Amount	$ 1,850,000
Derivative, Term of Contract	10 years
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 3 [Member] \| Borrowing Two [Member]
Derivative, Term of Contract	10 years
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 2 [Member] \| Borrowing One [Member]
Derivative, Term of Contract	7 years
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 2 [Member] \| Borrowing Two [Member]
Derivative, Term of Contract	7 years
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 1 [Member] \| Borrowing One [Member]
Derivative, Term of Contract	5 years
Federal Home Loan Bank Advances [Member] \| Individual Cash Flow Hedge Tied to FHLB, 1 [Member] \| Borrowing Two [Member]
Derivative, Notional Amount	$ 2,000,000
Derivative, Term of Contract	5 years

Federal Home Loan Bank Advances, Total Funding Available as a Percent of Total Assets.

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
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-SubTopic 470
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-Section S99
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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
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