Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Significant Accounting Policies
Number of operating segments | segment	4
Percentage of commercial and industrial loans not secured by real estate	21.70%	23.90%
Allowance for Credit Losses	$ 0	$ 0
Permanent write-offs	0	0	$ 0
Permanent write-offs	$ 0	0	0
Period when accrual of interest on loans is discontinued when loans are past due	90 days
Unrecognized tax position pertaining to interest and penalties	$ 0	0	0
Retained earnings	(272,705,000)	(280,426,000)
Allowance for credit losses on investments	213,000	0
Allowance for credit losses	35,843,000	31,146,000	$ 31,572,000	$ 34,246,000
Off balance sheet liability, Allowance for loan losses	$ 7,400,000	3,200,000
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Significant Accounting Policies
Retained earnings		4,500,000
Allowance for credit losses on investments		172,000
Allowance for credit losses		3,857,000
Off balance sheet liability, Allowance for loan losses		$ 1,900,000
Maximum
Significant Accounting Policies
Period when consumer loans are charged off when loans are past due	120 days