Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2021

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Schedule of net pension and retiree health benefit (income) cost

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

	Defined Benefit Pension Plans
	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Components of net periodic benefit cost:
Service cost	$	92.5	$	81.7	$	277.8	$	243.4
Interest cost	84.5		106.6		253.6		319.0
Expected return on plan assets	(237.5)		(229.5)		(712.7)		(671.4)
Amortization of prior service cost	1.0		1.1		3.2		3.2
Recognized actuarial loss	121.9		58.4		366.3		286.5
Net periodic benefit cost	$	62.4	$	18.3	$	188.2	$	180.7

	Retiree Health Benefit Plans
	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Components of net periodic benefit income:
Service cost	$	12.4	$	10.2	$	37.0	$	30.6
Interest cost	8.1		10.9		24.4		32.8
Expected return on plan assets	(36.5)		(40.3)		(109.6)		(115.1)
Amortization of prior service benefit	(14.9)		(21.9)		(44.7)		(51.6)
Recognized actuarial loss	0.8		0.7		2.4		2.1
Net periodic benefit income	$	(30.1)	$	(40.4)	$	(90.5)	$	(101.2)