EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Details) - Pension plan - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Net periodic pension cost included in the Bank's consolidated statements of income
Service cost	$ 323,000	$ 764,000	$ 767,000	$ 1,528,000
Interest cost	$ 436,000	$ 514,000	$ 943,000	$ 1,028,000
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	Labor and Related Expense	Labor and Related Expense
Expected return on plan assets	$ (615,000)	$ (1,031,000)	$ (1,347,000)	$ (2,062,000)
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	Labor and Related Expense	Labor and Related Expense
Amortization of net actuarial loss		$ 5,000		$ 10,000
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	Labor and Related Expense	Labor and Related Expense
Net periodic pension cost	$ 144,000	$ 252,000	$ 363,000	$ 504,000
Other disclosures
Employer contributions	$ 0	$ 0	$ 0	$ 0