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Note 10 - Intangible Assets (Details Textual) - USD ($)		3 Months Ended		12 Months Ended
	Oct. 25, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (Year)		4 years		4 years 73 days
Core Deposits [Member]
Finite-lived Intangible Assets Acquired
Core Deposits [Member] | Iowa State Savings Bank [Member]
Finite-lived Intangible Assets Acquired	$ 1,891,000

X

- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

+ Details

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X

- Definition

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Details

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X

- Details

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