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Investment Securities - Held-to-Maturity Securities Amortized Cost and Fair Value (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	$ 109,036,000	$ 137,413,000
Allowance for Credit Losses	0	0
Net Carrying Amount	109,036,000	137,413,000
Gross Unrealized Gains	6,149,000	2,378,000
Gross Unrealized (Losses)	0	(149,000)
Fair Value	115,185,000	139,642,000
Other assets
Debt Securities, Held-to-maturity [Abstract]
Accrued interest	366,000	469,000
MBS pass-through securities issued by FHLMC and FNMA
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	65,579,000	80,451,000
Allowance for Credit Losses	0	0
Net Carrying Amount	65,579,000	80,451,000
Gross Unrealized Gains	3,924,000	1,018,000
Gross Unrealized (Losses)	0	(144,000)
Fair Value	69,503,000	81,325,000
CMOs issued by FHLMC
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	27,201,000	31,477,000
Allowance for Credit Losses	0	0
Net Carrying Amount	27,201,000	31,477,000
Gross Unrealized Gains	1,441,000	685,000
Gross Unrealized (Losses)	0	(5,000)
Fair Value	28,642,000	32,157,000
CMOs issued by FNMA
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	8,042,000	10,210,000
Allowance for Credit Losses	0	0
Net Carrying Amount	8,042,000	10,210,000
Gross Unrealized Gains	363,000	282,000
Gross Unrealized (Losses)	0	0
Fair Value	8,405,000	10,492,000
CMOs issued by GNMA
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost		3,763,000
Allowance for Credit Losses		0
Net Carrying Amount		3,763,000
Gross Unrealized Gains		53,000
Gross Unrealized (Losses)		0
Fair Value		3,816,000
SBA-backed securities
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	6,547,000	7,999,000
Allowance for Credit Losses	0	0
Net Carrying Amount	6,547,000	7,999,000
Gross Unrealized Gains	400,000	265,000
Gross Unrealized (Losses)	0	0
Fair Value	6,947,000	8,264,000
Obligations of state and political subdivisions
Debt Securities, Held-to-maturity [Abstract]
Amortized Cost	1,667,000	3,513,000
Allowance for Credit Losses	0	0
Net Carrying Amount	1,667,000	3,513,000
Gross Unrealized Gains	21,000	75,000
Gross Unrealized (Losses)		0
Fair Value	$ 1,688,000	$ 3,588,000

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Debt Securities, Held-To-Maturity, After Allowance For Credit Loss

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Amount, before allowance for credit loss, of accrued interest on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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