Retirement Plans (Tables)

6 Months Ended

Mar. 31, 2024

Retirement Benefits [Abstract]

Schedule of Net Periodic Pension and Postretirement Cost (Benefit)

The Company’s net periodic pension and postretirement costs for its material plans were as follows:

	Three Months Ended March 31,				Six Months Ended March 31,
	2024		2023		2024		2023
Service cost	$	0.4	$	0.4	$	0.9	$	0.9
Interest cost	5.4		5.4		10.7		10.6
Expected return on plan assets	(4.8)		(5.5)		(9.7)		(10.9)
Recognized net actuarial loss	0.3		0.4		0.7		0.8
Defined benefit settlement loss	—		7.2		—		7.2
Net periodic cost	$	1.3	$	7.9	$	2.6	$	8.6