SHARE-BASED COMPENSATION PLANS - Narrative (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2018 USD ($)	Jun. 30, 2020 USD ($) installment	Jun. 30, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 12,191	$ 15,048
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting installments | installment		3
Stock Option and Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 3,253