Investment Securities - Net (losses) gains on trading securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Investment Securities
Net (losses) gain on sales transaction	$ (380)	$ 336	$ (1,620)	$ 456
Net mark to mark (losses) gains	(458)	268	(2,434)	(189)
Net (losses) gains on trading securities	$ (838)	$ 604	$ (4,054)	$ 267

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Name:	us-gaap_DebtSecuritiesTradingRealizedGainLoss
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration