Shareholders' Equity and Regulatory Matters - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Shareholders' Equity and Regulatory Matters
Total accumulated other comprehensive loss	$ (6,395)	$ (5,613)

Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
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-Section 45
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-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant