Bank segment - Schedule of Loan Modification (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024
Financing Receivable, Modified [Line Items]
Total	$ 2,156	$ 9,715
% of total class of loans	0.04%	0.16%
Term extension
Financing Receivable, Modified [Line Items]
Total	$ 153	$ 468
Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	153	153
Payment delay
Financing Receivable, Modified [Line Items]
Total	1,850	7,886
Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	1,208
Commercial
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
% of total class of loans	0.00%	0.00%
Commercial | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Commercial | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Consumer
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
% of total class of loans	0.00%	0.00%
Consumer | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Consumer | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Consumer | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	0
Consumer | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Residential 1-4 family | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 2,003	$ 7,232
% of total class of loans	0.08%	0.28%
Residential 1-4 family | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 153	$ 468
Residential 1-4 family | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Residential 1-4 family | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	1,850	6,764
Residential 1-4 family | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial real estate | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 1,208
% of total class of loans	0.00%	0.09%
Commercial real estate | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Commercial real estate | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial real estate | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial real estate | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	1,208
Home equity line of credit | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 153	$ 600
% of total class of loans	0.02%	0.06%
Home equity line of credit | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Home equity line of credit | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	153	153
Home equity line of credit | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	447
Home equity line of credit | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Residential land | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 675
% of total class of loans	0.00%	3.39%
Residential land | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Residential land | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Residential land | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	675
Residential land | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial construction | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
% of total class of loans	0.00%	0.00%
Commercial construction | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Commercial construction | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial construction | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	0
Commercial construction | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	0	0
Residential construction | Real estate
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
% of total class of loans	0.00%	0.00%
Residential construction | Real estate | Term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0
Residential construction | Real estate | Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Total	0	0
Residential construction | Real estate | Payment delay
Financing Receivable, Modified [Line Items]
Total	0	0
Residential construction | Real estate | Combination payment delay & term extension
Financing Receivable, Modified [Line Items]
Total	$ 0	$ 0