Bank segment - Troubled Debt Restructuring Narrative (Details) - Troubled debt restructurings real estate loans - USD ($)	3 Months Ended
Jun. 30, 2022	Dec. 31, 2022
Financing Receivable, Impaired [Line Items]
Financing receivable modifications minimum, period of payment default of loans determined to be TDRs (in days)	90 days
Commitments to lend additional funds to borrows with impaired or modified loans		$ 0

Amount of restructured debt contingently payable based on the occurrence of future events or circumstances.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 470
-SubTopic 60
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481408/470-60-50-2

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