Note 1 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands		3 Months Ended		12 Months Ended
	Jan. 01, 2020 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Assets, Total		$ 4,794,075	$ 3,784,586	$ 4,608,629
Loans and Leases Receivable, Net Amount, Total		3,584,442		3,479,676
Deposits, Total		$ 4,199,962		3,988,634
Number of Reportable Segments		2
Retained Earnings (Accumulated Deficit), Ending Balance		$ 362,607		353,574
Loans and Leases Receivable, Allowance, Impact of Accounting Policy Adoption			8,221
Off-Balance Sheet, Credit Loss, Liability, Ending Balance	$ 3,850				$ 350
Goodwill, Impairment Loss		0	$ 0	$ 0
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)				3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)				40 years
Accounting Standards Update 2016-13 [Member]
Retained Earnings (Accumulated Deficit), Ending Balance	8,800
Loans and Leases Receivable, Allowance, Impact of Accounting Policy Adoption	8,200
Off-Balance Sheet, Credit Loss, Liability, Ending Balance	3,500
Deferred Tax Assets, Net of Valuation Allowance, Total	2,900
Transfer of Loans From Purchased Credit Impaired to Purchased Credit Deteriorated [Member]
Loans and Leases Receivable, Net Amount, Total	$ 1,600
Kentucky Bancshares [Member]
Assets, Total		1,300,000
Loans and Leases Receivable, Net Amount, Total		766,000
Deposits, Total		1,000,000
Tangible Common Equity		$ 113,000