Borrowings and Subordinated Debentures - Additional Information (Detail) - Subordinated notes [Member] - USD ($)	12 Months Ended
	Dec. 31, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Debt Instrument, principal amount		$ 20,000,000.0
Subordinated borrowing due date	Oct. 01, 2030
Subordinated borrowing interest rate	5.00%
Subordinated borrowing interest rate basis	The notes mature October 1, 2030 and will initially bear interest at a fixed rate of 5.0% until October 1, 2025. From October 1, 2025 to the stated maturity date or early redemption date, the interest rate will reset semi-annually to an annual floating rate equal to the then-current three-month term Secured Overnight Financing Rate (SOFR) plus a spread of 475 basis points, but no less than 5.0%.
Minimum [Member]
Debt Instrument [Line Items]
Subordinated borrowing interest rate	5.00%
Secured Overnight Financing Rate (SOFR) [Member]
Debt Instrument [Line Items]
Basis points spread	475.00%