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Investment Securities - Available-for-Sale Securities Amortized Cost and Fair Value (Details) - USD ($) | Mar. 31, 2022 | Dec. 31, 2021
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Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | $ 995,637,000 | $ 1,169,520,000
Available-for-sale, gross unrealized gains | 879,000 | 11,074,000
Available-for-sale, gross unrealized losses | (41,059,000) | (13,026,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 955,457,000 | 1,167,568,000
Accrued interest | 3,300,000 | 3,700,000
Accumulated Other Comprehensive Income (Loss), Net of Tax |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, gross unrealized losses | (14,800,000) |
MBS pass-through securities issued by FHLMC, FNMA and GNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 133,883,000 | 316,090,000
Available-for-sale, gross unrealized gains | 252,000 | 1,224,000
Available-for-sale, gross unrealized losses | (5,486,000) | (2,784,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 128,649,000 | 314,530,000
CMOs issued by FHLMC |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 390,501,000 | 343,047,000
Available-for-sale, gross unrealized gains | 103,000 | 3,209,000
Available-for-sale, gross unrealized losses | (14,756,000) | (4,829,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 375,848,000 | 341,427,000
CMOs issued by FNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 43,750,000 | 48,187,000
Available-for-sale, gross unrealized gains | 9,000 | 152,000
Available-for-sale, gross unrealized losses | (2,258,000) | (611,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 41,501,000 | 47,728,000
CMOs issued by GNMA |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 40,948,000 | 56,345,000
Available-for-sale, gross unrealized gains | 3,000 | 99,000
Available-for-sale, gross unrealized losses | (1,725,000) | (553,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 39,226,000 | 55,891,000
SBA-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 56,085,000 | 32,640,000
Available-for-sale, gross unrealized gains | 11,000 | 993,000
Available-for-sale, gross unrealized losses | (1,444,000) | (155,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 54,652,000 | 33,478,000
Debentures of government- sponsored agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 150,091,000 | 191,449,000
Available-for-sale, gross unrealized gains | 3,000 | 25,000
Available-for-sale, gross unrealized losses | (6,797,000) | (2,947,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 143,297,000 | 188,527,000
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 11,890,000 | 11,886,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (917,000) | (256,000)
Allowance for Credit Losses | 0 |
Available-for-sale securities | 10,973,000 | 11,630,000
Obligations of state and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 129,706,000 | 129,009,000
Available-for-sale, gross unrealized gains | 498,000 | 5,372,000
Available-for-sale, gross unrealized losses | (5,514,000) | (381,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 124,690,000 | 134,000,000
Corporate bonds |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 36,988,000 | 39,001,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (2,128,000) | (506,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | 34,860,000 | 38,495,000
Asset-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, amortized cost | 1,795,000 | 1,866,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | (34,000) | (4,000)
Allowance for Credit Losses | 0 | 0
Available-for-sale securities | $ 1,761,000 | $ 1,862,000

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