Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2024

Retirement Benefits [Abstract]

Schedule of Net Pension and Retiree Health (Benefit) Cost

Net pension and retiree health (benefit) cost included the following components:

	Defined Benefit Pension Plans
	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Components of net periodic cost:
Service cost	$	85.6	$	74.9	$	169.4	$	145.3
Interest cost	165.7		162.6		330.7		323.7
Expected return on plan assets	(277.9)		(264.2)		(555.5)		(527.5)
Amortization of prior service cost	0.5		0.6		1.0		1.2
Recognized actuarial loss	31.8		30.9		62.4		60.9
Net periodic cost	$	5.7	$	4.8	$	8.0	$	3.6

	Retiree Health Benefit Plans
	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Components of net periodic benefit:
Service cost	$	9.5	$	8.2	$	17.7	$	15.9
Interest cost	15.6		15.3		31.1		30.7
Expected return on plan assets	(48.0)		(45.6)		(96.1)		(91.1)
Amortization of prior service benefit	(1.4)		(13.2)		(2.8)		(26.4)
Recognized actuarial gain	(0.7)		(2.0)		(1.3)		(2.9)
Net periodic benefit	$	(25.0)	$	(37.3)	$	(51.4)	$	(73.8)