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Investment Securities - Schedule of Held-to-Maturity Amortized Cost and Fair Value (Details) - USD ($) | Sep. 30, 2023 | Dec. 31, 2022
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Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | $ 935,142,000 | $ 972,207,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 935,142,000 | 972,207,000
Held-to-maturity, gross unrealized gains | 226,000 | 70,000
Held-to-maturity, gross unrealized losses | (152,152,000) | (127,038,000)
Total | 783,216,000 | 845,239,000
Accrued interest | 2,600,000 | 3,700,000
MBS pass-through securities issued by FHLMC, FNMA and GNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 311,595,000 | 331,281,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 311,595,000 | 331,281,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (61,870,000) | (50,147,000)
Total | 249,725,000 | 281,134,000
CMOs issued by FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 228,194,000 | 235,971,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 228,194,000 | 235,971,000
Held-to-maturity, gross unrealized gains | 71,000 | 59,000
Held-to-maturity, gross unrealized losses | (33,448,000) | (29,503,000)
Total | 194,817,000 | 206,527,000
CMOs issued by FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 104,031,000 | 111,904,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 104,031,000 | 111,904,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (9,125,000) | (5,419,000)
Total | 94,906,000 | 106,485,000
CMOs issued by GNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 51,268,000 | 52,356,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 51,268,000 | 52,356,000
Held-to-maturity, gross unrealized gains | 155,000 | 11,000
Held-to-maturity, gross unrealized losses | (4,816,000) | (3,076,000)
Total | 46,607,000 | 49,291,000
SBA-backed securities |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 1,853,000 | 2,372,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 1,853,000 | 2,372,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (140,000) | (133,000)
Total | 1,713,000 | 2,239,000
Debentures of government- sponsored agencies |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 146,050,000 | 145,823,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 146,050,000 | 145,823,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (28,893,000) | (26,467,000)
Total | 117,157,000 | 119,356,000
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 62,151,000 | 62,500,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 62,151,000 | 62,500,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (12,066,000) | (10,741,000)
Total | 50,085,000 | 51,759,000
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Debt securities, held-to-maturity | 30,000,000 | 30,000,000
Allowance for Credit Losses | 0 | 0
Net Carrying Amount | 30,000,000 | 30,000,000
Held-to-maturity, gross unrealized gains | 0 | 0
Held-to-maturity, gross unrealized losses | (1,794,000) | (1,552,000)
Total | $ 28,206,000 | $ 28,448,000

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