INCOME TAXES - Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
DEFERRED TAX ASSETS
Lease liabilities	$ 71.0	$ 37.0
Inventories	16.8	15.1
Accrued liabilities	65.6	63.0
Foreign tax credit carryovers	14.9	17.2
Net operating loss carryovers	14.2	14.7
Accounts receivable	8.5	5.9
Postretirement benefits	0.9	6.5
Other	4.1	7.2
Gross deferred tax assets	196.0	166.6
Valuation allowance	(32.3)	(33.8)
Total deferred tax assets	163.7	132.8
DEFERRED TAX LIABILITIES
Intangible assets	(73.3)	(65.6)
Lease right-of-use assets	(69.6)	(35.9)
Property, plant and equipment	(55.8)	(52.7)
Outside basis difference in equity investments	(7.2)	0.0
Other	(5.6)	(3.8)
Total deferred tax liabilities	(211.5)	(158.0)
Net deferred tax liability	$ (47.8)	$ (25.2)