SHARE-BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
SHARE-BASED COMPENSATION
Non-vested shares	226,674		226,674
Selling, general and administrative expenses
SHARE-BASED COMPENSATION
Total share-based compensation cost	$ 2.0	$ 3.4	$ 4.1	$ 5.3
Total income tax benefit recognized	0.3	0.3	0.5	0.6
Performance-Accelerated Restricted Share (PARS) Awards
SHARE-BASED COMPENSATION
Pretax compensation expense	1.7	3.1	3.5	4.7
Compensation Plan for Non-Employee Directors
SHARE-BASED COMPENSATION
Pretax compensation expense	0.3	$ 0.3	0.6	$ 0.6
Total unrecognized compensation cost related to share-based compensation arrangements	$ 13.1		$ 13.1
Weighted average period			1 year 9 months 18 days