Borrowings - Maximum aggregate balance of federal funds purchased and repurchase agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Maximum aggregate balance outstanding at any month-end	$ 150,692	$ 162,450
Average montly aggregate balance outstanding	$ 115,808	$ 107,305
Weighted average interest rate for the year	5.20%	2.15%
Weighted average interest rate at December 31	5.68%	4.23%