Note 20 - Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Loans held for sale, Total gains (losses)	$ 26	$ 3
Mortgage servicing rights, Total gains (losses)	0	0
Collateral dependent loans, Total gains (losses)	(287)	(46)
Total, Total gains (losses)	(261)	(43)
Fair Value, Nonrecurring [Member]
Loans held for sale	1,006	1,314
Mortgage servicing rights, net	2,709	2,986
Collateral dependent loans	3,856	1,978
Total	7,571	6,278
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Loans held for sale	0	0
Mortgage servicing rights, net	0	0
Collateral dependent loans	0	0
Total	0	0
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Loans held for sale	1,006	1,314
Mortgage servicing rights, net	0	0
Collateral dependent loans	3,856	1,978
Total	4,862	3,292
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Loans held for sale	0	0
Mortgage servicing rights, net	2,709	2,986
Collateral dependent loans	0	0
Total	$ 2,709	$ 2,986

Represents the amount of gain (loss) on fair value adjustments of collateral dependent loans during the period.

No definition available.

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- Definition

Represents the amount of gain (loss) on fair value adjustments of loans held for sale during the period.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of gain (loss) on fair value adjustments of mortgage servicing rights during the period.

+ References

No definition available.

+ Details

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- Definition

Represents the fair value portion of loans receivable adjustments based on appraised value of collateral.

+ References

No definition available.

+ Details

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Namespace Prefix:	hmnf_
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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

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- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481229/860-50-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-2

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