ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Schedule of Performance of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	$ 166,754	$ 78,186
30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	908	9,440
90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	382	207
Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	120,852	55,525
Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	44,612	13,014
Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	107,531	48,070
Commercial | Commercial and industrial | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	428
Commercial | Commercial and industrial | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Commercial and industrial | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	63,410	36,299
Commercial | Commercial and industrial | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	44,121	11,343
Commercial | Commercial mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	30,001	9,427
Commercial | Commercial mortgages | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Commercial mortgages | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Commercial mortgages | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	30,001	9,427
Commercial | Commercial mortgages | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	21,294	9,194
Commercial | Construction | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	8,285
Commercial | Construction | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Construction | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	21,294	909
Commercial | Construction | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Commercial | Owner-occupied commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		1,271
Commercial | Owner-occupied commercial | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		0
Commercial | Owner-occupied commercial | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		0
Commercial | Owner-occupied commercial | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		0
Commercial | Owner-occupied commercial | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		1,271
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	309	613
Residential | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Residential | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	0
Residential | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	613
Residential | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	309	0
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	7,619	9,611
Consumer | 30-89 Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	908	727
Consumer | 90+ Days Past Due and Still Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	382	207
Consumer | Accruing Current Balances
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	6,147	8,277
Consumer | Nonaccrual Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	$ 182	$ 400