OPERATIONS, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED AND RECENTLY ISSUED ACCOUNTING STANDARDS - Lease balance sheet (Details) $ in Thousands	9 Months Ended
	Mar. 31, 2020 USD ($)
OPERATIONS, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED AND RECENTLY ISSUED ACCOUNTING STANDARDS
Right-of-use assets - current	$ 608
Operating Lease, Right-of-Use Asset, Current, Statement of Financial Position [Extensible List]	us-gaap:PrepaidExpenseAndOtherAssetsCurrent
Right-of-use assets - non-current	$ 5,065
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent
Total right-of-use assets	$ 5,673
Lease liabilities - current	$ 549
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current
Lease liabilities - non-current	$ 6,128
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent
Total operating lease liabilities	$ 6,677