EMPLOYEE BENEFIT PLANS - Bank’s Pension Plan Asset Allocation (Details)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Pension Plan Assets
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Percentage of Plan Assets	100.00%	100.00%
Equity securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Target allocation	65.00%
Percentage of Plan Assets	62.60%	62.50%
Fixed income securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Target allocation	35.00%
Percentage of Plan Assets	37.40%	37.50%
Minimum | Equity securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Weighted-Average Expected Long-Term Rate of Return	5.00%
Minimum | Fixed income securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Weighted-Average Expected Long-Term Rate of Return	1.00%
Maximum | Equity securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Weighted-Average Expected Long-Term Rate of Return	9.00%
Maximum | Fixed income securities
Pension plan asset allocation, target allocation and expected long-term rate of return by asset category
Weighted-Average Expected Long-Term Rate of Return	4.00%