Retirement Benefits (Tables)

6 Months Ended

Mar. 31, 2022

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The components of net periodic benefit cost were (in millions):

	Pension Benefits
	Three Months Ended March 31,				Six Months Ended March 31,
	2022		2021		2022		2021
Service cost	$	20.3	$	22.9	$	40.7	$	45.6
Interest cost	32.4		31.5		64.8		62.8
Expected return on plan assets	(59.3)		(60.7)		(118.7)		(121.1)
Amortization:
Prior service cost	0.8		0.3		0.8		0.7
Net actuarial loss	22.3		36.8		44.6		73.5
Settlements	24.9		(0.2)		24.9		(0.4)
Net periodic benefit cost	$	41.4	$	30.6	$	57.1	$	61.1

	Other Postretirement Benefits
	Three Months Ended March 31,				Six Months Ended March 31,
	2022		2021		2022		2021
Service cost	$	0.2	$	0.2	$	0.4	$	0.5
Interest cost	0.3		0.3		0.6		0.6
Amortization:
Prior service credit	(0.2)		(1.3)		(0.4)		(2.7)
Net actuarial loss	0.1		0.3		0.3		0.6
Net periodic benefit cost (credit)	$	0.4	$	(0.5)	$	0.9	$	(1.0)