OTHER COMPREHENSIVE INCOME (LOSS) - Summary of OCI (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), pre-tax	$ 4,455		$ 5,883		$ 1,411	$ 19,173
Total other comprehensive income (loss), tax	494		(1,108)		787	(1,257)
Total other comprehensive income (loss), net of taxes	4,949	$ (2,751)	4,775	$ 13,141	2,198	17,916
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), pre-tax	6,049		1,739		3,730	13,862
Total other comprehensive income (loss), tax	0		0		0	0
Total other comprehensive income (loss), net of taxes	6,049		1,739		3,730	13,862
Pension and other defined benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), pre-tax	177		1,585		1,023	3,735
Total other comprehensive income (loss), tax	(37)		(340)		(215)	(784)
Total other comprehensive income (loss), net of taxes	140		1,245		808	2,951
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), pre-tax	(1,771)		2,559		(3,342)	1,576
Total other comprehensive income (loss), tax	531		(768)		1,002	(473)
Total other comprehensive income (loss), net of taxes	$ (1,240)		$ 1,791		$ (2,340)	$ 1,103