Note 2 - Acquisition (Details Textual)					3 Months Ended			6 Months Ended	9 Months Ended		12 Months Ended
		Mar. 07, 2022 USD ($)	May 31, 2021 USD ($)		Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Business Combination, Consideration Transferred, Total									$ 167,913,000	$ 232,946,000
Debt Securities, Held-to-Maturity, Fair Value, Total					$ 433,371,000				433,371,000		$ 0
Goodwill, Ending Balance					202,524,000		$ 135,830,000	$ 135,830,000	202,524,000	135,830,000	135,830,000	$ 202,524,000	$ 136,529,000	$ 12,513,000
Business Combination, Acquisition Related Costs					0		525,000		19,500,000	19,025,000
Proceeds from Sale of Debt Securities, Available-for-sale			$ 91,000,000			$ 2,000,000			2,111,000	91,094,000
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				66,694,000		0
Business Combination, Acquired Receivable, Fair Value		540,000,000
Business Combination, Acquired Receivables, Gross Contractual Amount		$ 549,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					11,900,000				26,800,000
Commonwealth [Member] | Merger Related Credit Loss [Member]
Business Combination, Acquisition Related Costs								$ 7,400,000	4,400,000
Commonwealth [Member] | Pre-tax Merger Expenses [Member]
Business Combination, Acquisition Related Costs							525,000		24,100,000	18,500,000
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		123,317,000
Business Combination, Acquired Receivable, Fair Value											724,000,000
Business Combination, Acquired Receivables, Gross Contractual Amount											723,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual							$ 11,300,000			15,700,000
Number of Branches Acquired			19
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] | Merger Related Credit Loss [Member]
Business Combination, Acquisition Related Costs										7,400,000
Kentucky Bancshares [Member] | Pre-tax Merger Expenses [Member]
Business Combination, Acquisition Related Costs										$ 18,500,000

[1] Calculation of CDI related to the acquisition. During the third quarter of 2021, a provisional period adjustment of $999,000 was recorded based on revised inputs used in the CDI calculation.

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

[3] Adjustment to other assets to reflect the estimated fair value of prepaid and other assets. During the third quarter of 2021, a provisional period adjustment of $70,000 was recorded for the write off of miscellaneous mortgage servicing fees.