INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 10,748	$ 2,034	$ 20,417	$ 8,373
Income before taxes	27,860	2,929	67,029	19,880
Restructuring charges	7,562	3,104	18,362	9,538
Restructuring charges, net of tax	5,651	3,005	13,951	7,153
Effective income tax rate reconciliation, disposition of business	949		(5,291)
Effective income tax rate reconciliation, disposition of business, net of tax	766		(5,251)
Other tax expense (benefit) that affect comparability	$ 1,913	(1,413)	$ (115)	(580)
Effective income tax rate reconciliation, acquisition cost		2,960		2,960
Effective income tax rate reconciliation, acquisition cost, net of tax		2,321		2,321
Effective income tax rate reconciliation, debt extinguishment loss		6,690		6,690
Effective income tax rate reconciliation, debt extinguishment loss, net of tax		$ 5,245		$ 5,245
Effective tax rate	30.00%	35.90%	31.10%	34.40%