Benefit Plans - Schedule of Expected Benefit Payments (Detail)	Jun. 30, 2022 USD ($)
Atlas Bank Retirement Income Plan ("ABRIP") [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	$ 146,000
2024	144,000
2025	145,000
2026	146,000
2027	142,000
2028-2032	648,000
Benefit Equalization Plan ("BEP") [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	240,000
2024	236,000
2025	232,000
2026	227,000
2027	222,000
2028-2032	1,017,000
Postretirement Welfare Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	50,000
2024	60,000
2025	69,000
2026	85,000
2027	94,000
2028-2032	577,000
Directors' Consultation and Retirement Plan ("DCRP") [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	71,000
2024	92,000
2025	134,000
2026	153,000
2027	171,000
2028-2032	1,238,000
Supplemental Executive Retirement Plan (SERP) member
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	0
2024	0
2025	0
2026	0
2027	0
2028-2032	$ 437,000

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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