Business Combination & Asset Purchase - Summary of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed Recognized (Detail) - USD ($) $ in Thousands				12 Months Ended
	Oct. 01, 2022	Oct. 01, 2021	Apr. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023
Assets
Goodwill				$ 86,358		$ 86,358
Peoples Federal Savings and Loan [Member]
Business Acquisition [Line Items]
Cash	$ 9,806			$ 9,806
Common Shares	13,446
Treasury stock repurchased	(3)
Total	23,249
Assets
Cash and cash equivalents	18,881
Other securities, at cost	1,271
Loans, net	101,755
Premises and equipment	1,906
Goodwill	5,924
Other assets	12,081
Total Assets Purchased	141,818
Deposits
Noninterest bearing	7,139
Interest bearing	104,719
Total deposits	111,858
Federal Home Loan Bank (FHLB) advances	896
Accrued expenses and other liabilities	5,815
Total Liabilities Assumed	$ 118,569
Perpetual Federal Savings Bank [Member]
Business Acquisition [Line Items]
Cash		$ 59,234			$ 59,234
Common Shares		41,078
Total		100,312
Assets
Cash and cash equivalents		44,975
Federal funds sold		1,672
Interest-bearing time deposits		6,250
Other securities, at cost		2,794
Loans, net		334,661
Premises and equipment		615
Goodwill		25,220
Other assets		3,975
Total Assets Purchased		420,162
Deposits
Noninterest bearing		2,018
Interest bearing		309,090
Total deposits		311,108
Federal Home Loan Bank (FHLB) advances		6,218
Accrued expenses and other liabilities		2,524
Total Liabilities Assumed		$ 319,850
Ossian Financial Services, Inc. [Member]
Business Acquisition [Line Items]
Cash			$ 20,001
Total			20,001
Assets
Cash and cash equivalents			20,229
Interest-bearing time deposits			20,226
Securities - available-for-sale			30,243
Other securities, at cost			281
Loans, net			52,403
Premises and equipment			494
Goodwill			7,874
Other assets			5,308
Total Assets Purchased			137,058
Deposits
Noninterest bearing			34,509
Interest bearing			81,535
Total deposits			116,044
Accrued expenses and other liabilities			1,013
Total Liabilities Assumed			$ 117,057