Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2021

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

Schedule of Net Benefit (Credits) Costs [Table Text Block]

The components of net periodic benefit cost (credit) are as follows:

	Pension Benefits
	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
	(in millions)
Service cost	$	0.5	$	0.5	$	1.0	$	1.0
Interest cost	4.3		5.4		8.6		10.8
Expected asset return	(9.7)		(9.7)		(19.4)		(19.3)
Amortized loss	2.7		2.2		5.4		4.3
Net periodic benefit credit	$	(2.2)	$	(1.6)	$	(4.4)	$	(3.2)
	Other Postretirement Benefits
	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
	(in millions)
Service cost	$	0.1	$	0.1	$	0.2	$	0.2
Interest cost	2.1		2.5		4.2		5.1
Amortized loss	0.4		0.3		0.8		0.5
Amortized prior service credit	(0.4)		(0.4)		(0.8)		(0.8)
Net periodic benefit cost	$	2.2	$	2.5	$	4.4	$	5.0