Fair Value - Carrying Amounts and Estimated Fair Values of Company's Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financial Assets:
Interest Bearing Time Deposits with Banks	$ 500	$ 500
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(6,980,908)	(6,989,742)
Time Deposits	(1,285,520)	(1,289,537)
Carrying Value
Financial Assets:
Cash and Short-term Investments	123,927	118,382
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	5,734,746	5,755,551
Accrued Interest Receivable	37,683	38,997
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,695,388)	(5,700,205)
Time Deposits	(1,285,520)	(1,289,537)
Short-term Borrowings	(30,362)	(43,852)
Long-term Debt	(138,873)	(138,831)
Accrued Interest Payable	(6,936)	(10,243)
Estimate of Fair Value Measurement
Financial Assets:
Cash and Short-term Investments	123,927	118,382
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	5,681,915	5,702,933
Accrued Interest Receivable	37,683	38,997
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,695,388)	(5,700,205)
Time Deposits	(1,280,698)	(1,286,002)
Short-term Borrowings	(30,362)	(43,852)
Long-term Debt	(137,371)	(137,018)
Accrued Interest Payable	(6,936)	(10,243)
Estimate of Fair Value Measurement | Level 1
Financial Assets:
Cash and Short-term Investments	75,956	71,428
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	0	0
Accrued Interest Receivable	0	0
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,695,388)	(5,700,205)
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	0	0
Accrued Interest Payable	0	0
Estimate of Fair Value Measurement | Level 2
Financial Assets:
Cash and Short-term Investments	47,971	46,954
Interest Bearing Time Deposits with Banks	500	500
Loans, Net	0	0
Accrued Interest Receivable	8,716	9,496
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	(1,280,698)	(1,286,002)
Short-term Borrowings	(30,362)	(43,852)
Long-term Debt	(102,613)	(102,892)
Accrued Interest Payable	(6,637)	(9,925)
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	5,681,915	5,702,933
Accrued Interest Receivable	28,967	29,501
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	(34,758)	(34,126)
Accrued Interest Payable	$ (299)	$ (318)