Note 3 - Business Combinations (Details Textual) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	Oct. 09, 2024 USD ($) shares	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Oct. 08, 2024 $ / shares	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)
Assets		$ 4,084,640	$ 4,084,640			$ 3,907,713	$ 3,832,978
Deposits		3,323,550	3,323,550			$ 3,095,611
HMN Financial Inc. (HNMF) [Member]
Assets					$ 1,100,000
Financing Receivable, after Allowance for Credit Loss					876,600
Investments					199,000
Deposits					$ 983,200
Subsequent Event [Member]
Assets	$ 5,500,000
Financing Receivable, after Allowance for Credit Loss	3,800,000
Deposits	4,300,000
Assets under Management, Carrying Amount	$ 43,600,000
Subsequent Event [Member] | HMN Financial Inc. (HNMF) [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner	21.90%
Home Federal [Member] | Subsequent Event [Member]
Business Combination, Consideration Transferred	$ 128,800
Share Price (in dollars per share) | $ / shares				$ 22.9
Home Federal [Member] | Subsequent Event [Member] | US Midwest Region [Member]
Number of Branches	29
HMN Financial Inc. (HNMF) [Member]
Business Combination, Acquisition Related Costs		$ 1,700	$ 2,300
HMN Financial Inc. (HNMF) [Member] | Subsequent Event [Member]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Shares Exchanged per Share (in shares) | shares	1.25
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares	5,547,658
HMN Financial Inc. (HNMF) [Member] | Subsequent Event [Member] | MINNESOTA
Number of Branches	12
HMN Financial Inc. (HNMF) [Member] | Subsequent Event [Member] | IOWA
Number of Branches	1
HMN Financial Inc. (HNMF) [Member] | Subsequent Event [Member] | WISCONSIN
Number of Branches	1