v3.26.1
BORROWINGS, SUBORDINATED NOTES AND DEBENTURES - NARRATIVE (Details)
 1 Months Ended 3 Months Ended 12 Months Ended
Apr. 08, 2026
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Oct. 01, 2025
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Sep. 19, 2025
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Jun. 05, 2025
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Sep. 27, 2024
USD ($)
Jul. 15, 2024
USD ($)
Apr. 30, 2024
USD ($)
Mar. 06, 2024
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Jan. 28, 2019
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Dec. 13, 2004
USD ($)
Feb. 28, 2022
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Dec. 31, 2025
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Jun. 30, 2026
USD ($)
bank
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Jun. 30, 2019
USD ($)
Sep. 30, 2020
USD ($)
Debt Instrument [Line Items]                                  
Borrowings, subordinated notes and debentures                         $ 342,915,000 $ 312,671,000      
Gain (loss) on extinguishment                         0 729,000 $ 973,000    
Percentage of principal amount redeemed   100.00%                              
Borrowings from other banks                                  
Debt Instrument [Line Items]                                  
Maximum borrowing capacity                         0 0      
Federal Reserve Bank Advances                                  
Debt Instrument [Line Items]                                  
Short-term borrowings outstanding                         0 0      
Maximum borrowing capacity                         9,581,000,000 7,046,500,000      
Federal Funds | Borrowings from other banks                                  
Debt Instrument [Line Items]                                  
Maximum borrowing capacity                         $ 250,000,000.0        
Federal funds lines of credit, number of banks | bank                         5        
Secured lines of credit                                  
Debt Instrument [Line Items]                                  
Maximum borrowing capacity                         $ 150,000,000        
Borrowings, subordinated notes and debentures                         0 0      
Unsecured line of credit                                  
Debt Instrument [Line Items]                                  
Maximum borrowing capacity                         95,000,000        
Borrowings, subordinated notes and debentures                         0 $ 0      
Subordinated loans                                  
Debt Instrument [Line Items]                                  
Borrowings, subordinated notes and debentures                         $ 7,400,000        
Subordinated notes                 $ 7,500,000                
Subordinated notes maturity (in months)                 15 months                
Effective rate (as percent)                 6.25%                
Repayment of subordinated loans                               $ 100,000  
Subordinated notes                                  
Debt Instrument [Line Items]                                  
Subordinated notes                     $ 150,000,000           $ 175,000,000
Repayment of subordinated loans       $ 1,400,000 $ 9,200,000 $ 2,600,000 $ 4,800,000 $ 4,200,000                  
Borrowings interest rate (as percent)                                 4.875%
Basis spread on variable rate                     2.27%            
Debt instrument, repurchased face amount       1,500,000 9,500,000 3,000,000.0 5,000,000.0 5,000,000.0                  
Gain (loss) on extinguishment       $ 100,000 $ 200,000 $ 400,000 $ 200,000 $ 700,000                  
Percentage of principal amount redeemed                     4.00%            
Subordinated notes | Fixed-to-Floating Rate Subordinated Notes due 2030                                  
Debt Instrument [Line Items]                                  
Debt instrument, repurchased face amount   $ 160,500,000                              
Subordinated notes | Fixed-to-Floating Rate Subordinated Notes due 2035                                  
Debt Instrument [Line Items]                                  
Subordinated notes     $ 200,000,000                            
Borrowings interest rate (as percent)     7.00%                            
Basis spread on variable rate     3.79%                            
Junior subordinated debentures                                  
Debt Instrument [Line Items]                                  
Effective rate (as percent)                         6.30%        
Basis spread on variable rate                         0.26%        
Trust preferred securities                   $ 5,000,000.0              
Borrowings, subordinated notes and debentures                         $ 5,200,000        
Basis margin on variable rate                         0.024        
Subordinated Loans                                  
Debt Instrument [Line Items]                                  
General and administrative expense                       $ 7,000,000.0          
Repayment of subordinated loans $ 7,400,000