FAIR VALUE - LEVEL 3 UNREALIZED GAIN (LOSS) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value adjustment	$ 0	$ 0	$ 743
Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest income on investments	0	0	311
Fair value adjustment	0	0	743
Total	$ 0	$ 0	$ 1,054