Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Schedule Of Defined Benefit Plans Disclosures [Table Text Block]

For the three month periods ended March 31, 2021 and 2020, the components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following (in millions): 

	Pension Benefits				Other Postretirement Benefits
	Three months ended March 31,				Three months ended March 31,
	2021		2020		2021		2020
Service cost - benefits earned during the year	$	3.8	$	3.2	$	0.3	$	0.5
Interest cost on benefits earned in prior years	17.1		21.5		2.1		2.7
Expected return on plan assets	(34.1)		(33.6)		—		—
Amortization of prior service cost (credit)	0.2		0.2		(0.7)		(0.9)
Amortization of net actuarial loss	18.9		18.6		3.3		2.7
Total retirement benefit expense	$	5.9	$	9.9	$	5.0	$	5.0