Note 17 - Regulatory Capital (Details Textual)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Capital Conservation Buffer		1.875%
Scenario, Forecast [Member]
Capital Conservation Buffer	2.50%

Percentage of common equity tier 1 capital above its minimum risk-based capital requirements in order to avoid limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers.

No definition available.

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Namespace Prefix:	hmnf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration