EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Details) - Pension plan - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Net periodic pension cost included in the Bank's consolidated statements of income
Service cost	$ 1,534,000	$ 2,315,000
Interest cost	$ 1,885,000	$ 1,813,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Labor and Related Expense	Labor and Related Expense
Expected return on plan assets	$ (2,694,000)	$ (3,749,000)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Labor and Related Expense	Labor and Related Expense
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Labor and Related Expense	Labor and Related Expense
Settlement loss		$ 334,000
Net periodic pension cost	$ 725,000	713,000
Amounts recognized in accumulated other comprehensive (gain) loss, before tax effect
Amounts recognized in accumulated other comprehensive loss, before tax, net actuarial gain (losses)	$ 5,200,000	$ (668,000)