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Investment Securities - Available-for-Sale Securities Amortized Cost and Fair Value (Details) - USD ($)		Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		$ 1,169,520,000	$ 373,038,000
Gross Unrealized Gains		11,074,000	19,393,000
Gross Unrealized (Losses)		(13,026,000)	(80,000)
Allowance for Credit Losses	[1]	0	0
Securities available for sale, Fair Value		1,167,568,000	392,351,000
Other assets
Debt Securities, Available-for-sale [Line Items]
Accrued interest		3,700,000	1,900,000
MBS pass-through securities issued by FHLMC and FNMA
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		316,090,000	50,686,000
Gross Unrealized Gains		1,224,000	2,530,000
Gross Unrealized (Losses)		(2,784,000)	0
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		314,530,000	53,216,000
CMOs issued by FHLMC
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		343,047,000	143,267,000
Gross Unrealized Gains		3,209,000	7,925,000
Gross Unrealized (Losses)		(4,829,000)	(1,000)
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		341,427,000	151,191,000
CMOs issued by FNMA
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		48,187,000	16,450,000
Gross Unrealized Gains		152,000	580,000
Gross Unrealized (Losses)		(611,000)	0
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		47,728,000	17,030,000
CMOs issued by GNMA
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		56,345,000	6,863,000
Gross Unrealized Gains		99,000	351,000
Gross Unrealized (Losses)		(553,000)	0
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		55,891,000	7,214,000
SBA-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		32,640,000	30,941,000
Gross Unrealized Gains		993,000	1,976,000
Gross Unrealized (Losses)		(155,000)	(55,000)
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		33,478,000	32,862,000
Debentures of government sponsored agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		191,449,000	19,944,000
Gross Unrealized Gains		25,000	266,000
Gross Unrealized (Losses)		(2,947,000)	(24,000)
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		188,527,000	20,186,000
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		11,886,000
Gross Unrealized Gains		0
Gross Unrealized (Losses)		(256,000)
Allowance for Credit Losses		0
Securities available for sale, Fair Value		11,630,000
Obligations of state and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		129,009,000	104,887,000
Gross Unrealized Gains		5,372,000	5,765,000
Gross Unrealized (Losses)		(381,000)	0
Allowance for Credit Losses		0	0
Securities available for sale, Fair Value		134,000,000	$ 110,652,000
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		39,001,000
Gross Unrealized Gains		0
Gross Unrealized (Losses)		(506,000)
Allowance for Credit Losses		0
Securities available for sale, Fair Value		38,495,000
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		1,866,000
Gross Unrealized Gains		0
Gross Unrealized (Losses)		(4,000)
Allowance for Credit Losses		0
Securities available for sale, Fair Value		$ 1,862,000
[1] Refer to Note 1, Summary of Accounting Policies, for information on the adoption of ASU 2016-13 in 2020.

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