Note 5 - Premises and Equipment (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Depreciation, Total	$ 3,984,000	$ 3,602,000	$ 2,859,000
Construction and Repairs of Buildings [Member] \| Director [Member]
Related Party Transaction, Amounts of Transaction	$ 2,207,000	$ 2,633,000	$ 5,934,000

Amount of transactions with related party during the financial reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration