RESTRUCTURING CHARGES - Summary of the Restructuring and Other Related Charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 7,562	$ 3,104	$ 18,362	$ 9,538
Personnel related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	782	1,658	3,264	3,792
Facilities, exit costs and other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,283	914	6,807	1,054
Non-cash facility and other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,497	532	8,291	4,692
Cost of goods and services
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,337	1,353	9,762	4,076
Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,225	$ 1,751	$ 8,600	$ 5,462