Investment Securities - Summary of Available-For-Sale Securities and Held to Maturity Securities, Continuous Unrealized Loss Position, Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Investments Debt And Equity Securities [Line Items]
Less than 12 months fair value	$ 40,371	$ 14,723
Less than 12 months unrealized losses	(437)	(193)
12 months or longer fair value	4,712
12 months or longer unrealized losses	(288)
Fair value	45,083	14,723
Unrealized losses	(725)	(193)
Mortgage backed securities [Member]
Investments Debt And Equity Securities [Line Items]
Less than 12 months fair value	28,621	4,481
Less than 12 months unrealized losses	(360)	(17)
Fair value	28,621	4,481
Unrealized losses	(360)	(17)
Government agencies [Member]
Investments Debt And Equity Securities [Line Items]
Less than 12 months fair value		2,412
Less than 12 months unrealized losses		(6)
Fair value		2,412
Unrealized losses		(6)
Corporate bonds [Member]
Investments Debt And Equity Securities [Line Items]
Less than 12 months fair value	11,750	7,830
Less than 12 months unrealized losses	(77)	(170)
12 months or longer fair value	4,712
12 months or longer unrealized losses	(288)
Fair value	16,462	7,830
Unrealized losses	$ (365)	$ (170)

Investments debt and equity securities.

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

+ References

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This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

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