Loans - Amortized cost basis of loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 1,585
% of Total Class of Financing Receivable	0.10%
Term Extension
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 1,366
Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost	219
Commercial real estate | Term Extension
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 1,127
% of Total Class of Financing Receivable	0.20%
Commercial real estate | Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 45
% of Total Class of Financing Receivable	0.00%
Commercial business | Term Extension
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 169
% of Total Class of Financing Receivable	0.10%
Commercial business | Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 174
% of Total Class of Financing Receivable	0.20%
Residential mortgage | Term Extension
Financing Receivable, Modifications [Line Items]
Amortized Cost	$ 70
% of Total Class of Financing Receivable	0.00%