Fair Value Measurements and Disclosures - Off-balance sheet financial instruments (Details) - Level 2 - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Carrying amount \| Commitments to extend credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	$ 505,018	$ 421,399
Carrying amount \| Letters of credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	17,711	8,928
Fair value \| Commitments to extend credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	$ 1,712	$ 6,932

The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

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