Loan Portfolio and Allowance for Credit Losses - Allowance For Credit Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$ 0	$ 0
Collectively evaluated for impairment	52,994	52,205
Total ending allowance balance	52,994	52,205	$ 50,606	$ 50,248
Loans:
Individually evaluated for impairment	26,448	25,768
Collectively evaluated for impairment	5,263,730	5,226,692
Total loans	5,290,178	5,252,460
Commercial Loans [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,133	3,081
Total ending allowance balance	3,133	3,081	3,023	3,420
Loans:
Individually evaluated for impairment	2,059	2,083
Collectively evaluated for impairment	314,704	311,360
Total loans	316,763	313,443
1 to 4 Family Residential Real Estate [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	49,652	48,895
Total ending allowance balance	49,652	48,895	47,307	46,636
Loans:
Individually evaluated for impairment	24,350	23,663
Collectively evaluated for impairment	4,938,448	4,903,798
Total loans	4,962,798	4,927,461
Installment Loans [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	209	229
Total ending allowance balance	209	229	$ 276	$ 192
Loans:
Individually evaluated for impairment	39	22
Collectively evaluated for impairment	10,578	11,534
Total loans	$ 10,617	$ 11,556