RESTRUCTURING CHARGES - Amounts Expected to be Incurred, Amounts Incurred, and Amounts Remaining to Be Incurred (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	$ 34.8
Amounts Incurred During the Three Months Ended December 31, 2025	8.2	$ 3.3
Amounts Remaining to be Incurred	26.6
Employee separation costs
Restructuring and Related Costs [Line Items]
Amounts Incurred During the Three Months Ended December 31, 2025	4.5
Other restructuring costs
Restructuring and Related Costs [Line Items]
Amounts Incurred During the Three Months Ended December 31, 2025	3.7
Customized Polymer Solutions
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.7
Amounts Incurred During the Three Months Ended December 31, 2025	0.4
Amounts Remaining to be Incurred	0.3
Customized Polymer Solutions | Employee separation costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.5
Amounts Incurred During the Three Months Ended December 31, 2025	0.4
Amounts Remaining to be Incurred	0.1
Customized Polymer Solutions | Other restructuring costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.2
Amounts Incurred During the Three Months Ended December 31, 2025	0.0
Amounts Remaining to be Incurred	0.2
Durable Metal Solutions
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	11.7
Amounts Incurred During the Three Months Ended December 31, 2025	2.0
Amounts Remaining to be Incurred	9.7
Durable Metal Solutions | Employee separation costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	3.9
Amounts Incurred During the Three Months Ended December 31, 2025	1.0
Amounts Remaining to be Incurred	2.9
Durable Metal Solutions | Other restructuring costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	7.8
Amounts Incurred During the Three Months Ended December 31, 2025	1.0
Amounts Remaining to be Incurred	6.8
Sustainable Fiber Solutions
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	22.3
Amounts Incurred During the Three Months Ended December 31, 2025	5.8
Amounts Remaining to be Incurred	16.5
Sustainable Fiber Solutions | Employee separation costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	4.0
Amounts Incurred During the Three Months Ended December 31, 2025	3.1
Amounts Remaining to be Incurred	0.9
Sustainable Fiber Solutions | Other restructuring costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	18.3
Amounts Incurred During the Three Months Ended December 31, 2025	2.7
Amounts Remaining to be Incurred	15.6
Innovative Closure Solutions
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.1
Amounts Incurred During the Three Months Ended December 31, 2025	0.0
Amounts Remaining to be Incurred	0.1
Innovative Closure Solutions | Employee separation costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.1
Amounts Incurred During the Three Months Ended December 31, 2025	0.0
Amounts Remaining to be Incurred	0.1
Innovative Closure Solutions | Other restructuring costs
Restructuring and Related Costs [Line Items]
Total Amounts Expected to be Incurred	0.0
Amounts Incurred During the Three Months Ended December 31, 2025	0.0
Amounts Remaining to be Incurred	$ 0.0