Note 7 - Goodwill and Identifiable Intangible Assets - Gross Carrying Amount of Intangible Assets and Accumulated Amortization (Details) - Core Deposits [Member] - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Gross Carrying Amount	$ 56,808	$ 56,808
Accumulated Amortization	$ (56,164)	$ (55,973)

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(16))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant