Note 1 - Basis of Presentation and Summary of Significant Accounting Policies (Details Textual)		1 Months Ended	3 Months Ended	9 Months Ended
	Jan. 01, 2020 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	May 01, 2019	Jan. 01, 2019 USD ($)
Repayments of Subordinated Debt, Total				$ (0)	$ 3,609,000
Number of Operating Segments				2
Loans and Leases Receivable, Net Amount, Total			$ 3,421,980,000	$ 3,421,980,000		$ 2,818,225,000
Retained Earnings (Accumulated Deficit), Ending Balance			341,970,000	341,970,000		333,699,000
Loans and Leases Receivable, Net Amount, Total	$ 8,200,000		0	8,221,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance	3,850,000		$ 6,000,000	$ 6,000,000		$ 350,000		$ 3,900,000
Accounting Standards Update 2016-13 [Member]
Retained Earnings (Accumulated Deficit), Ending Balance	(8,800,000)
Loans and Leases Receivable, Net Amount, Total	8,200,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance	3,500,000
Deferred Tax Assets, Net of Valuation Allowance, Total	2,900,000
Transfer of Loans From Purchased Credit Impaired to Purchased Credit Deteriorated [Member]
Loans and Leases Receivable, Net Amount, Total	$ 1,600,000
Subordinated Notes Assumed in the king Acquisition [Member]
Repayments of Subordinated Debt, Total		$ 4,000,000
KBST [Member]
Noncontrolling Interest, Ownership Percentage by Parent							100.00%