RESTRUCTURING CHARGES - Schedule of Accrued Liability for the Restructuring and Related Charges (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2024	Jun. 30, 2023
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	$ 12,873	$ 12,999	$ 19,658	$ 17,572	$ 483	$ 650	$ 19,658	$ 650
Restructuring charges	18,688	2,401	12,400	3,862	78,334
Cash payment	(7,016)	(2,527)	(10,577)	(4,824)	(2,127)	(167)
Non-cash charges	(14,497)		(8,482)		(59,118)
Accrued liability ending balance	10,048	12,873	12,999	16,610	17,572	483	10,048	16,610
Personnel related costs
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	8,613	8,739	14,107	8,118	312	386	14,107	386
Restructuring charges	709	482	1,847	2,234	8,050
Cash payment	(2,671)	(608)	(7,215)	(579)	(244)	(74)
Non-cash charges	0		0		0
Accrued liability ending balance	6,651	8,613	8,739	9,773	8,118	312	6,651	9,773
Facilities & Exit Costs
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	4,260	4,260	5,551	9,454	171	264	5,551	264
Restructuring charges	3,482	1,919	2,071	1,628	11,166
Cash payment	(4,345)	(1,919)	(3,362)	(4,245)	(1,883)	(93)
Non-cash charges	0		0		0
Accrued liability ending balance	3,397	4,260	4,260	6,837	9,454	171	3,397	6,837
Non-cash facility and other costs
Restructuring Reserve [Roll Forward]
Accrued liability beginning balance	0	0	0	0	0	0	0	0
Restructuring charges	14,497	0	8,482	0	59,118
Cash payment	0	0	0	0	0	0
Non-cash charges	(14,497)		(8,482)		(59,118)
Accrued liability ending balance	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0