Investment Securities - Available-for-Sale Securities Amortized Cost and Fair Value (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
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

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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-Section 50
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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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