Fair Value Measurements and Derivative Instruments (Tables)

3 Months Ended

Dec. 31, 2023

Derivative Instruments Gain Loss [Line Items]

Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables summarize the financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2023 and September 30, 2023:

	December 31, 2023
	Carrying Value		Level 1		Level 2		Level 3
Other assets:
Investments held by Rabbi Trust	$	11.8	$	11.8	$	—	$	—
Interest rate derivative contracts		4.1		—		4.1		—
Total assets	$	15.9	$	11.8	$	4.1	$	—
Other liabilities:
Obligation to Rabbi Trust	$	11.8	$	11.8	$	—	$	—
Total liabilities	$	11.8	$	11.8	$	—	$	—

	September 30, 2023
	Carrying Value		Level 1		Level 2		Level 3
Other assets:
Investments held by Rabbi Trust	$	10.9	$	10.9	$	—	$	—
Interest rate derivative contracts		21.3		—		21.3		—
Total Assets	$	32.2	$	10.9	$	21.3	$	—
Other liabilities:
Obligation to Rabbi Trust	$	10.9	$	10.9	$	—	$	—
Total Liabilities	$	10.9	$	10.9	$	—	$	—

Interest Rate Contracts

Derivative Instruments Gain Loss [Line Items]

Summary of Effects on Consolidated Financial Statements of Designated As Cash Flow Hedges

The effects on the consolidated financial statements of the interest rate contracts which were designated as cash flow hedges were as follows:

	Three Months Ended December 31,
	2023			2022
Income (Loss) recognized in Other comprehensive (loss)	$	(14.5	)	$	-
Net income (loss) reclassified from Accumulated other comprehensive income into Interest expense		2.9			3.0