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Investment Securities - Available-for-Sale Securities Amortized Cost and Fair Value (Details) - USD ($) | Jun. 30, 2023 | Dec. 31, 2022
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Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | $ 856,166,000 | $ 892,605,000
Available-for-sale, gross unrealized gains | 69,000 | 34,000
Available-for-sale, gross unrealized losses | (85,293,000) | (90,543,000)
Allowance for Credit Losses | 0 | 0
Fair Value | $ 770,942,000 | $ 802,096,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] | Interest receivable and other assets | Interest receivable and other assets
Accrued interest | $ 3,100,000 | $ 3,200,000
MBS pass-through securities issued by FHLMC, FNMA and GNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 102,420,000 | 109,736,000
Available-for-sale, gross unrealized gains | 2,000 | 3,000
Available-for-sale, gross unrealized losses | (11,758,000) | (12,133,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 90,664,000 | 97,606,000
CMOs issued by FHLMC |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 333,374,000 | 347,437,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (32,162,000) | (33,682,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 301,212,000 | 313,755,000
CMOs issued by FNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 32,916,000 | 36,172,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (3,816,000) | (3,852,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 29,100,000 | 32,320,000
CMOs issued by GNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 32,193,000 | 35,120,000
Available-for-sale, gross unrealized gains | 31,000 | 0
Available-for-sale, gross unrealized losses | (3,377,000) | (3,296,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 28,847,000 | 31,824,000
SBA-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 39,824,000 | 47,724,000
Available-for-sale, gross unrealized gains | 0 | 2,000
Available-for-sale, gross unrealized losses | (3,175,000) | (3,371,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 36,649,000 | 44,355,000
Debentures of government- sponsored agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 149,129,000 | 149,114,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (13,261,000) | (14,008,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 135,868,000 | 135,106,000
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 11,914,000 | 11,904,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (1,580,000) | (1,635,000)
Allowance for Credit Losses | 0 |
Fair Value | 10,334,000 | 10,269,000
Obligations of state and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 116,040,000 | 116,855,000
Available-for-sale, gross unrealized gains | 36,000 | 29,000
Available-for-sale, gross unrealized losses | (13,160,000) | (14,761,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 102,916,000 | 102,123,000
Corporate bonds |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 36,991,000 | 36,990,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (2,948,000) | (3,714,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 34,043,000 | 33,276,000
Asset-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 1,365,000 | 1,553,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (56,000) | (91,000)
Allowance for Credit Losses | 0 | 0
Fair Value | $ 1,309,000 | $ 1,462,000

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