RESTRUCTURING CHARGES - Summary of Accrued Liability for the Restructuring and Related Charges (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2020
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	$ 2,130	$ 1,513	$ 0	$ 0
Restructuring charges	1,633	3,104	6,434
Cash payments	(1,208)	(1,955)	(761)
Non-cash charges		(532)	(4,160)	(4,692)
Accrued liability ending balance	2,555	2,130	1,513	2,555
Personnel related costs
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	2,130	1,513	0	0
Restructuring charges	1,050	1,658	2,134
Cash payments	(828)	(1,041)	(621)
Non-cash charges		0	0
Accrued liability ending balance	2,352	2,130	1,513	2,352
Facilities, exit costs and other
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	0	0	0	0
Restructuring charges	583	914	140
Cash payments	(380)	(914)	(140)
Non-cash charges		0	0
Accrued liability ending balance	203	0	0	203
Facility and Other Costs
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	0	0	0	0
Restructuring charges	0	532	4,160
Cash payments	0	0	0
Non-cash charges		(532)	(4,160)
Accrued liability ending balance	$ 0	$ 0	$ 0	$ 0