Fair Value - Carrying Amounts and Estimated Fair Values of Company's Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financial Assets:
Interest Bearing Time Deposits with Banks	$ 500	$ 500
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,135,871)	(5,350,051)
Time Deposits	(701,516)	(428,469)
Carrying Value
Financial Assets:
Cash and Short-term Investments	132,419	119,079
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	3,830,578	3,724,804
Accrued Interest Receivable	29,115	27,741
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(4,434,355)	(4,921,582)
Time Deposits	(701,516)	(428,469)
Short-term Borrowings	(158,303)	(101,161)
Long-term Debt	(127,890)	(102,645)
Accrued Interest Payable	(5,890)	(1,513)
Estimate of Fair Value Measurement
Financial Assets:
Cash and Short-term Investments	132,419	119,079
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	3,725,317	3,688,903
Accrued Interest Receivable	29,115	27,741
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(4,434,355)	(4,921,582)
Time Deposits	(698,642)	(426,184)
Short-term Borrowings	(158,303)	(101,161)
Long-term Debt	(124,263)	(99,102)
Accrued Interest Payable	(5,890)	(1,513)
Estimate of Fair Value Measurement | Level 1
Financial Assets:
Cash and Short-term Investments	72,063	77,174
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	0	0
Accrued Interest Receivable	0	38
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(4,434,355)	(4,921,582)
Time Deposits	0	0
Short-term Borrowings	(117,000)	(36,200)
Long-term Debt	0	0
Accrued Interest Payable	0	0
Estimate of Fair Value Measurement | Level 2
Financial Assets:
Cash and Short-term Investments	60,356	41,905
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	0	0
Accrued Interest Receivable	9,634	10,863
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	(698,642)	(426,184)
Short-term Borrowings	(41,303)	(64,961)
Long-term Debt	(51,983)	(26,830)
Accrued Interest Payable	(5,417)	(1,205)
Estimate of Fair Value Measurement | Level 3
Financial Assets:
Cash and Short-term Investments	0	0
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	3,725,317	3,688,903
Accrued Interest Receivable	19,481	16,840
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	(72,280)	(72,272)
Accrued Interest Payable	$ (473)	$ (308)