Business Combination and Asset Purchase - Summary of Carrying Amount of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Oct. 01, 2021	Apr. 30, 2021
Perpetual Federal Savings Bank [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	$ 471	$ 510	$ 728
Perpetual Federal Savings Bank [Member] | Consumer Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	536	581	608
Perpetual Federal Savings Bank [Member] | Agricultural Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment		114	118
Perpetual Federal Savings Bank [Member] | Commercial Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	2	5	234
Perpetual Federal Savings Bank [Member] | Commercial and Industrial [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment			$ 5
Perpetual Federal Savings Bank [Member] | Agricultural Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	110
Ossian Financial Services, Inc. [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	187	208		$ 1,309
Ossian Financial Services, Inc. [Member] | Consumer Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	21	22		24
Ossian Financial Services, Inc. [Member] | Agricultural Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment				981
Ossian Financial Services, Inc. [Member] | Commercial Real Estate [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	210	222		315
Ossian Financial Services, Inc. [Member] | Commercial and Industrial [Member]
Business Acquisition [Line Items]
Carrying amount, net of fair value adjustment	$ 277	$ 285		$ 314