Funds Borrowed - Additional Information (Detail) - USD ($)							3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
		Sep. 30, 2023	Jul. 10, 2023	Feb. 28, 2021	Dec. 31, 2007	Jun. 30, 2007	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2019	Dec. 31, 2022	Apr. 30, 2021	Mar. 15, 2021	Dec. 31, 2020	Aug. 31, 2019	Mar. 31, 2019	Dec. 31, 2017
Debt Instrument [Line Items]
Listing services deposits from other financial institutions.		$ 12,100,000					$ 12,100,000			$ 12,100,000			$ 12,400,000
Retail savings deposit balance		$ 18,000,000					18,000,000			18,000,000
Aggregate principal amount																	$ 6,000,000
Maturity date		Sep. 30, 2028		Feb. 28, 2026
Gain loss on sales of loans net							$ 1,417,000	$ 518,000		$ 4,578,000	$ 5,061,000
Issue of common stock		28,965,885					28,965,885			28,965,885			28,663,827
Preferred securities repurchased from a third party investor					$ 2,000,000
Long-term debt	[1]	$ 218,137,000					$ 218,137,000			$ 218,137,000			$ 214,320,000
Investment securities pledged		53,175,000					53,175,000			53,175,000			$ 48,492,000
Medallion Capital, Inc.
Debt Instrument [Line Items]
Debt instrument face amount			$ 20,000,000
Long-term debt		5,000,000					5,000,000			5,000,000
Debt instrument leverage fee			200,000
Debt instrument, additional leverage fee			$ 400,000
Line Of Credit Facility Drawn Amount		4,800,000					4,800,000			4,800,000
Line Of Credit Facility Drawable Amount		10,300,000					10,300,000			10,300,000
Long term debt under capital infusion		2,500,000					2,500,000			2,500,000
Preferred Securities [Member]
Debt Instrument [Line Items]
Maturity date									Sep. 30, 2037
Sale of preferred securities						$ 35,000,000
Issue of common stock						1,083
Preferred securities outstanding		$ 33,000,000					$ 33,000,000			$ 33,000,000
Preferred Securities [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.13%
Preferred Securities [Member] | SOFR Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.13%
Description of variable rate basis									26 basis points
Preferred Securities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Aggregate principal amount of unsecured junior subordinated notes						$ 36,100,000
Small Business Administration Debentures and Borrowings [Member]
Debt Instrument [Line Items]
Debt instrument interest rate Percentage		3.25%					3.25%			3.25%
Loan commitment term										4 years 6 months
Commitment fee percentage										1.00%
Principal amount of loan																			$ 34,000,000
Extended maturity date										Apr. 30, 2024
Debt instrument outstanding amount		$ 70,700,000					$ 70,700,000			$ 70,700,000
Debt instrument remaining amount		500,000					500,000			500,000
FSVC's [Member]
Debt Instrument [Line Items]
Principal amount of loan																			$ 33,500,000
Federal reserve discount window and other borrowings [Member]
Debt Instrument [Line Items]
Debt instrument outstanding amount		0					0			0
Investment securities pledged		37,000,000					37,000,000			$ 37,000,000
Pledged securities advance rate of fair value										100.00%
Borrowing capacity		37,000,000					37,000,000			$ 37,000,000
Commercial Banks [Member]
Debt Instrument [Line Items]
Line of credit outstanding										10,000,000
Debt instrument remaining amount		65,000,000					65,000,000			65,000,000
Borrowing capacity		75,000,000					75,000,000			75,000,000
7.25% Unsecured Senior Notes Due February 2026 [Member]
Debt Instrument [Line Items]
Aggregate principal amount														$ 3,000,000	$ 3,300,000
7.50% Unsecured Senior Notes Due December 2027 [Member]
Debt Instrument [Line Items]
Aggregate principal amount														$ 11,700,000
Privately Placed Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount		$ 39,000,000		$ 25,000,000			$ 39,000,000			$ 39,000,000					$ 8,500,000	$ 33,600,000		$ 30,000,000
Debt instrument interest rate Percentage		9.25%		7.25%			9.25%			9.25%						7.50%		8.25%
Maturity date										2024
Maturity date										Dec. 31, 2027
Repurchase amount		$ 33,000,000					$ 33,000,000			$ 33,000,000								$ 33,000,000
Principal amount remaining outstanding		3,000,000					3,000,000			3,000,000
Gain loss on sales of loans net												$ 4,100,000
Minimum [Member]
Debt Instrument [Line Items]
Time deposits		$ 250,000					$ 250,000			$ 250,000
Brokerage [Member] | Maximum [Member]
Debt Instrument [Line Items]
Average brokerage fee percentage in relation to the maturity of deposits										0.15%

[1] Includes $4.1 million and $3.2 million of deferred financing costs as of September 30, 2023 and December 31, 2022. Refer to Note 5 for more details.