Allowance for credit losses - Allowance for loan losses - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Modifications [Line Items]
Accumulated loans modified to borrowers under financial difficulties		$ 1,644,647
Allowance for loan and lease losses reserve	$ 5,800
Commercial
Financing Receivable, Modifications [Line Items]
Accumulated loans modified to borrowers under financial difficulties		324,425
Outstanding commitments to lend additional funds to debtors owing receivables whose terms have been modified in troubled debt restructurings	$ 5,000	$ 12,000

Amount of increase (decrease) of allowance reserve for credit loss.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

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- Definition

Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18794-111554

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