Note 14 - Share Repurchase (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Sep. 30, 2018	Sep. 30, 2018	May 14, 2014
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			750,000
Stock Repurchased and Retired During Period, Shares	675
Stock Repurchased and Retired During Period, Value	$ 23,000	$ (22,759)

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration