Investment Securities - Available-for-Sale Securities Amortized Cost and Fair Value (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	$ 911,476,000	$ 1,169,520,000
Available-for-sale, gross unrealized gains	7,000	11,074,000
Available-for-sale, gross unrealized losses	(98,990,000)	(13,026,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	812,493,000	1,167,568,000
Accrued interest	3,100,000	3,700,000
MBS pass-through securities issued by FHLMC, FNMA and GNMA
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	113,941,000	316,090,000
Available-for-sale, gross unrealized gains	3,000	1,224,000
Available-for-sale, gross unrealized losses	(13,702,000)	(2,784,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	100,242,000	314,530,000
CMOs issued by FHLMC
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	357,486,000	343,047,000
Available-for-sale, gross unrealized gains	0	3,209,000
Available-for-sale, gross unrealized losses	(35,575,000)	(4,829,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	321,911,000	341,427,000
CMOs issued by FNMA
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	38,125,000	48,187,000
Available-for-sale, gross unrealized gains	0	152,000
Available-for-sale, gross unrealized losses	(4,177,000)	(611,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	33,948,000	47,728,000
CMOs issued by GNMA
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	36,747,000	56,345,000
Available-for-sale, gross unrealized gains	0	99,000
Available-for-sale, gross unrealized losses	(3,459,000)	(553,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	33,288,000	55,891,000
SBA-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	48,372,000	32,640,000
Available-for-sale, gross unrealized gains	4,000	993,000
Available-for-sale, gross unrealized losses	(3,585,000)	(155,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	44,791,000	33,478,000
Debentures of government- sponsored agencies
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	149,106,000	191,449,000
Available-for-sale, gross unrealized gains	0	25,000
Available-for-sale, gross unrealized losses	(14,185,000)	(2,947,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	134,921,000	188,527,000
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	11,899,000	11,886,000
Available-for-sale, gross unrealized gains	0	0
Available-for-sale, gross unrealized losses	(1,741,000)	(256,000)
Allowance for Credit Losses	0
Available-for-sale securities	10,158,000	11,630,000
Obligations of state and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	117,161,000	129,009,000
Available-for-sale, gross unrealized gains	0	5,372,000
Available-for-sale, gross unrealized losses	(18,734,000)	(381,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	98,427,000	134,000,000
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	36,989,000	39,001,000
Available-for-sale, gross unrealized gains	0	0
Available-for-sale, gross unrealized losses	(3,787,000)	(506,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	33,202,000	38,495,000
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, amortized cost	1,650,000	1,866,000
Available-for-sale, gross unrealized gains	0	0
Available-for-sale, gross unrealized losses	(45,000)	(4,000)
Allowance for Credit Losses	0	0
Available-for-sale securities	$ 1,605,000	$ 1,862,000

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, after allowance for credit loss, of accrued interest on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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