Bank segment - Collateral - Dependent loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Nonaccrual [Line Items]
Consumer mortgage loans collateralized by residential real estate property in foreclosure process	$ 4,800	$ 3,400
Residential real estate property | Real estate | Residential 1-4 family
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	5,731	2,272
Residential real estate property | Real estate | Home equity line of credit
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	1,674	1,135
Collateral pledged
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	18,739	14,756
Collateral pledged | Real estate
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	18,453	14,455
Commercial real estate | Real estate | Commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	11,048	11,048
Business assets | Commercial
Financing Receivable, Nonaccrual [Line Items]
Collateral-dependent loans, amortized cost	$ 286	$ 301