INCOME TAXES - Narratives (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Tax Contingency [Line Items]
Statutory tax rate		21.00%	21.00%	21.00%
Net operating losses		$ 59.0	$ 52.0
US and non-US Tax Credit Carryforward		$ 9.0
US and non-US tax credit carryforward expiration period		2026
Effect of unrecognized tax benefits on effective tax rate		$ 23.0	14.0
Accrual for income tax penalties and interest		5.0	4.0
Deferred Federal Income Tax Expense (Benefit)		(32.0)	$ (6.0)	$ 28.0
Undistributed Earnings of Foreign Subsidiaries		30.0
Forecast
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Expected Reduction	$ 2.0
State
Income Tax Contingency [Line Items]
Net operating losses		$ 780.0
Minimum
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Year		2026
Maximum
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Year		2045
UNITED KINGDOM | Foreign Country Jurisdiction
Income Tax Contingency [Line Items]
Net operating losses		$ 93.0
GERMANY | Foreign Country Jurisdiction
Income Tax Contingency [Line Items]
Net operating losses		$ 66.0