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Business Combination & Asset Purchase - Summary of Carrying Amount of Loans (Parenthetical) (Detail) - USD ($)	Dec. 31, 2021	Oct. 01, 2021	Apr. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Perpetual Federal Savings Bank [Member]
Business Acquisition [Line Items]
Fair value adjustment	$ 189,800	$ 237,200
Ossian Financial Services, Inc. [Member]
Business Acquisition [Line Items]
Fair value adjustment	$ 320,600		$ 324,800
Limberlost Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Fair value adjustment				$ 0	$ 62,000	$ 2,118,000

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