Note 2 - Business Combination (Unaudited) (Details Textual) - First of Long Island Corporation [Member] $ / shares in Units, $ in Millions	Sep. 04, 2024 USD ($) $ / shares
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 14,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans	11,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	$ 11,000
Business Acquisition, Equity Interest Issued or Issuable, Share Exchange Ratio	0.5175
Business Combination, Consideration Transferred	$ 284
Share Price (in dollars per share) \| $ / shares	$ 23.97

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 8
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479637/805-30-30-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 30
-Paragraph 7
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479637/805-30-30-7

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration