Benefit Plans - Schedule of Expected Benefit Payments (Details) $ in Thousands	Jun. 30, 2026 USD ($)
Atlas Bank Retirement Income Plan ("ABRIP")
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2027	$ 134
2028	132
2029	130
2030	127
2031	124
2032-2036	563
Benefit Equalization Plan ("BEP")
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2027	178
2028	179
2029	179
2030	179
2031	178
2032-2036	831
Postretirement Welfare Plan
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2027	64
2028	81
2029	97
2030	105
2031	160
2032-2036	476
Directors' Consultation and Retirement Plan ("DCRP")
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2027	177
2028	193
2029	248
2030	295
2031	254
2032-2036	1,252
Supplemental Executive Retirement Plan (SERP)
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
2027	0
2028	0
2029	0
2030	0
2031	0
2032-2036	$ 1,219

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
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

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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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