LEASES - Summary of Future Maturities of Lease Payments for Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Operating Leases
2020	$ 19,128
2021	34,484
2022	26,884
2023	20,180
2024	18,214
2025	12,376
Thereafter	63,859
Total lease payments	195,125
Less: Imputed Interest	(35,726)
Present value of lease liabilities	159,399	$ 167,902
Finance Leases
2021	2,381
2021	3,087
2022	2,749
2023	2,195
2024	2,077
2025	2,075
Thereafter	7,777
Total lease payments	22,341
Less: Imputed Interest	(4,281)
Present value of lease liabilities	$ 18,060	$ 18,691