Investment Securities - Net gains (losses) on trading securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Investment Securities
Net gains (losses) on sales transaction	$ 7	$ (380)	$ (40)	$ (1,620)
Net mark to mark losses	(195)	(458)	(201)	(2,434)
Net losses on trading securities	$ (188)	$ (838)	$ (241)	$ (4,054)

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-14

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

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