v3.26.1
Borrowings (Details)
$ in Thousands
12 Months Ended
Oct. 01, 2025
USD ($)
Jun. 30, 2026
USD ($)
Institution
Jun. 30, 2025
USD ($)
Sep. 17, 2025
Sep. 15, 2021
USD ($)
Investor
Sep. 17, 2020
USD ($)
Investor
Borrowings [Abstract]            
Long-term fixed rate borrowings   $ 6,166 $ 4,189      
Amount outstanding   0 0      
Repayment of subordinated notes payable   20,000 0      
Other long-term borrowings   0        
Federal Home Loan Bank of New York [Member]            
Borrowings [Abstract]            
Loans pledged as collateral   721,400 634,600      
Federal Reserve Bank [Member]            
Borrowings [Abstract]            
Collateral amount available to be pledged against potential borrowings   15,900 18,200      
Amount outstanding   $ 0 0      
Subordinated Note Purchase Agreements Entered on September 17, 2020 [Member]            
Borrowings [Abstract]            
Number of qualified institutional investors (in Investor) | Investor           14
Interest rate           4.75%
Debt instrument, due date   Sep. 17, 2030        
Aggregate principal amount           $ 20,000
Debt issuance costs           $ 424
Debt issuance cost, amortization period   60 months        
Debt Instrument Floating Rate       8.99%    
Repayment of subordinated notes payable $ 20,000          
Subordinated Note Purchase Agreement Entered on September 15, 2021 [Member]            
Borrowings [Abstract]            
Number of qualified institutional investors (in Investor) | Investor         18  
Interest rate         3.00%  
Debt instrument, due date   Sep. 15, 2031        
Aggregate principal amount         $ 30,000  
Debt issuance costs         $ 499  
Debt issuance cost, amortization period   60 months        
Outstanding borrowings, net of issuance costs   $ 29,900 29,900      
The Bank of Greene County [Member]            
Borrowings [Abstract]            
Maximum borrowing capacity   15,000        
The Bank of Greene County [Member] | Federal Home Loan Bank of New York [Member]            
Borrowings [Abstract]            
Loans pledged as collateral   721,400        
Maximum amount of funding available   450,600        
Overnight borrowings from Federal Home Loan Bank   119,000 74,000      
Long-term fixed rate borrowings   6,200 4,200      
Municipal letters of credit from Federal Home Loan Bank   70,000 90,000      
The Bank of Greene County [Member] | Other Financial Institution [Member]            
Borrowings [Abstract]            
Maximum borrowing capacity   $ 90,000        
Number of other financial institutions (in Institution) | Institution   3        
The Bank of Greene County [Member] | Federal Home Loan Bank 0.0% Development Advance Program [Member] | Federal Home Loan Bank of New York [Member]            
Borrowings [Abstract]            
Interest rate   0.00%        
The Bank of Greene County [Member] | Federal Home Loan Bank 0.0% Development Advance Program [Member] | Federal Home Loan Bank of New York [Member] | Federal Home Loan Bank Maturity Period One [Member]            
Borrowings [Abstract]            
Long-term fixed rate borrowings   $ 2,200 $ 2,200      
Long term fixed interest rate   3.80% 3.80%      
Fixed interest rate, maturity period   Oct. 31, 2027        
The Bank of Greene County [Member] | Federal Home Loan Bank 0.0% Development Advance Program [Member] | Federal Home Loan Bank of New York [Member] | Federal Home Loan Bank Maturity Period Two [Member]            
Borrowings [Abstract]            
Long-term fixed rate borrowings   $ 2,000        
Long term fixed interest rate   4.20%        
Fixed interest rate, maturity period   Jun. 30, 2028 Jun. 30, 2028      
The Bank of Greene County [Member] | Federal Home Loan Bank 0.0% Development Advance Program [Member] | Federal Home Loan Bank of New York [Member] | Federal Home Loan Bank Maturity Period Three [Member]            
Borrowings [Abstract]            
Long-term fixed rate borrowings   $ 2,000        
Long term fixed interest rate   4.20%        
Fixed interest rate, maturity period   Jun. 30, 2029