Note 2 - Acquisition (Details Textual)					3 Months Ended		12 Months Ended
		Mar. 07, 2022 USD ($)	May 31, 2021 USD ($)		Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Business Combination, Consideration Transferred, Total					$ 167,913,000	$ 0
Debt Securities, Held-to-Maturity, Fair Value, Total					535,807,000		$ 0
Goodwill, Ending Balance					202,524,000	12,513,000	135,830,000	$ 12,513,000
Business Combination, Acquisition Related Costs					19,500,000	400,000
Proceeds from Sale of Debt Securities, Available-for-sale			$ 91,000,000		2,111,000	0
Goodwill, Purchase Accounting Adjustments					0	0
Commonwealth [Member]
Business Combination, Consideration Transferred, Total		$ 167,913,000
Number of Branches		15
Debt Securities, Held-to-Maturity, Fair Value, Total		$ 162,000,000
Goodwill, Ending Balance		67,000,000			66,694,000		0
Business Combination, Acquired Receivable, Fair Value		539,600,000
Business Combination, Acquired Receivables, Gross Contractual Amount		$ 548,800,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					3,200,000	0
Commonwealth [Member] | Merger Related Credit Loss [Member]
Business Combination, Acquisition Related Costs					4,400,000
Commonwealth [Member] | Pre-tax Merger Expenses [Member]
Business Combination, Acquisition Related Costs					24,100,000
Commonwealth [Member] | Jefferson County in Kentucky [Member]
Number of Branches		9
Commonwealth [Member] | Shelby County in Kentucky [Member]
Number of Branches		4
Commonwealth [Member] | Northern Kentucky [Member]
Number of Branches		2
Kentucky Bancshares [Member]
Business Combination, Consideration Transferred, Total			232,946,000
Goodwill, Ending Balance					123,317,000		123,317,000
Business Combination, Acquired Receivable, Fair Value			723,500,000
Business Combination, Acquired Receivables, Gross Contractual Amount			$ 723,300,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					$ 10,900,000	0
Number of Branches Acquired			19
Goodwill, Purchase Accounting Adjustments			$ (14,000,000.0)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	[1],[2]		999,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Prepaid and Other Assets			$ (70,000)	[2],[3]			(70,000)
Kentucky Bancshares [Member] | Core Deposits [Member]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles							$ 999,000
Kentucky Bancshares [Member] | Pre-tax Merger Expenses [Member]
Business Combination, Acquisition Related Costs						$ 400,000

[1] Calculation of core deposit intangible related to the acquisition. During the third quarter of 2021, a recast adjustment of $999,000 was recorded based on revised inputs used in the calculation of the CDI attributed to KB, resulting in an increased intangible value.

[2] See the following page for explanations or individual fair value and recast adjustments.

[3] Adjustment to other assets to reflect the estimated fair value of prepaid and other assets. During the third quarter of 2021, a recast adjustment of $70,000 was recorded for the write off of miscellaneous mortgage servicing fees accrued in other assets by KB at acquisition, resulting in a reduction to other assets.