Note 6 - Goodwill and Other Intangible Asset (Details Textual) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 2,700
Goodwill, Impairment Loss			$ 0
Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life	8 years

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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