Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
Dec. 31, 2021 USD ($) Segment	Dec. 31, 2020 USD ($)
Accounting Policies [Line Items]
Cash reserve balances with the FRB	$ 0	$ 0
Interest-bearing deposits in banks mature within one year and are carried at cost	$ 100,000
Percentage of loan portfolio secured by real estate	76.00%
Number of reportable segment \| Segment	1
Building
Accounting Policies [Line Items]
Premises and equipment, estimated useful life	40 years
Maximum
Accounting Policies [Line Items]
Interest-bearing deposits maturity	1 year
Percentage of capital on secured loan amount issued	20.00%
Secured loan amount	$ 41,000,000
Percentage of capital on unsecured loan amount issued	10.00%
Unsecured loan amount	$ 21,000,000
Maximum \| Core Deposits
Accounting Policies [Line Items]
Intangible assets, estimated useful life	10 years
Maximum \| Furniture And Equipment
Accounting Policies [Line Items]
Premises and equipment, estimated useful life	25 years
Minimum \| Core Deposits
Accounting Policies [Line Items]
Intangible assets, estimated useful life	3 years
Minimum \| Furniture And Equipment
Accounting Policies [Line Items]
Premises and equipment, estimated useful life	3 years

Accounting policies.

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Interest-bearing deposits in banks mature within one year and are carried at cost.

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Interest bearing deposits maturity.

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Percentage of loan portfolio secured by real estate.

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Secured loans amount in percentage of capital.

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Unsecured loans amount in percentage of capital.

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- Definition

Cash deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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