DEBT - Short-Term Debt (Details) - USD ($)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Short-term Debt [Line Items]
Short-term debt	$ 0	$ 4,200,000
Weighted-average interest rate	0.00%	3.30%
Short-term Lines of Credit
Short-term Debt [Line Items]
Borrowing capacity	$ 87,800,000	$ 113,500,000
Short-term debt	0	2,300,000
Letter of credit
Short-term Debt [Line Items]
Undrawn letters of credit	6,000,000.0	6,300,000
Bank Guarantee
Short-term Debt [Line Items]
Undrawn letters of credit	$ 45,700,000	$ 97,100,000
Minimum | Short-term Lines of Credit
Short-term Debt [Line Items]
Interest rate spread	0.80%	0.40%
Maximum | Short-term Lines of Credit
Short-term Debt [Line Items]
Interest rate spread	7.30%	7.30%