Fair Value by Balance Sheet grouping (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$ 219,180,000	$ 189,728,000
Investment Owned, at Fair Value	1,754,140,000	1,733,696,000
Mortgages Held-for-sale, Fair Value Disclosure	$ 9,387,000	$ 2,149,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Derivative Asset	$ 300,000	$ 46,000
Impaired loans carried at fair value	1,103,000	5,773,000
Other Assets, Fair Value Disclosure	6,783,848,000	6,918,326,000
Loans Receivable, Fair Value Disclosure	6,794,671,000	6,926,294,000
Time Deposits, Fair Value	714,307,000	552,443,000
Other Liabilities, Fair Value Disclosure	1,465,000	1,325,000
Deposits, Fair Value Disclosure	715,772,000	553,768,000
Short-term Debt, Fair Value	238,786,000	227,342,000
Subordinated Debt Obligations, Fair Value Disclosure	207,912,000	177,928,000
Swaps, fair value	226,000
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	262,000
Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value	$ 2,129,000	$ 1,859,000
Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Swaps, fair value	$ 226,000	$ 243,000
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$ 219,180,000	$ 189,728,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Loans Receivable, Fair Value Disclosure	$ 0	$ 0
Other Liabilities, Fair Value Disclosure	1,465,000	1,325,000
Deposits, Fair Value Disclosure	1,465,000	1,325,000
Level 1 | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value	$ 1,630,000	$ 1,420,000
Level 1 | Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Level 1 | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value	$ 1,754,140,000	$ 1,726,696,000
Mortgages Held-for-sale, Fair Value Disclosure	$ 9,387,000	$ 2,149,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Loans Receivable, Fair Value Disclosure	$ 9,720,000	$ 2,195,000
Time Deposits, Fair Value	714,307,000	552,443,000
Deposits, Fair Value Disclosure	714,307,000	552,443,000
Short-term Debt, Fair Value	238,786,000	227,342,000
Subordinated Debt Obligations, Fair Value Disclosure	$ 207,912,000	$ 177,928,000
Level 2 | Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Level 2 | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ 262,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value		$ 7,000,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Impaired loans carried at fair value	$ 1,103,000	$ 5,773,000
Other Assets, Fair Value Disclosure	6,783,848,000	6,918,326,000
Loans Receivable, Fair Value Disclosure	6,784,951,000	6,924,099,000
Deposits, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value	$ 499,000	$ 439,000
Fair Value, Inputs, Level 3 [Member] | Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Fair Value, Inputs, Level 3 [Member] | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ 0
Estimate of Fair Value Measurement [Member] | Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	219,180,000	$ 189,728,000
Investment Owned, at Fair Value	1,754,140,000	1,733,696,000
Mortgages Held-for-sale, Fair Value Disclosure	$ 9,387,000	$ 2,149,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Impaired loans carried at fair value	$ 1,103,000	$ 5,773,000
Other Assets, Fair Value Disclosure	6,777,102,000	7,048,544,000
Loans Receivable, Fair Value Disclosure	6,787,925,000	7,056,512,000
Time Deposits, Fair Value	711,660,000	554,445,000
Other Liabilities, Fair Value Disclosure	1,465,000	1,325,000
Deposits, Fair Value Disclosure	713,125,000	555,770,000
Short-term Debt, Fair Value	238,786,000	227,342,000
Subordinated Debt Obligations, Fair Value Disclosure	188,210,000	188,667,000
Reported Value Measurement [Member] | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Owned, at Fair Value	$ 2,129,000	$ 1,859,000
Reported Value Measurement [Member] | Loans Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities
Reported Value Measurement [Member] | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets
Derivative Liability, Type [Extensible Enumeration]	Other Liabilities	Other Liabilities