Note 7 - Income Taxes - Tax Credits and Other Tax Benefits Recognized and Amortization Expense Related to Tax Credit Partnerships (Details) (Parentheticals)	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration]	Deferred income tax expense (benefit)	Deferred income tax expense (benefit)	Deferred income tax expense (benefit)	Deferred income tax expense (benefit)

Indicates line item in statement of cash flows that includes amortization expense for investment that generates income tax credit and other income tax benefit under tax credit program accounted for using proportional amortization method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478156/740-323-50-1A

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Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration