FAIR VALUE OF FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($)
12 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Realized net gain to earnings from AOCI $ 30,500  
Investment security, interest income 2,700,000  
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt $ 497,500,000 $ 487,500,000