Pension and Other Post-Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2018

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Components of pension and other post retirement benefit costs

The following table shows the components of our pension and other post-retirement benefits expense for the three months ended June 30, 2018 and 2017 (in millions):

	2018 Pension Benefits			2017 Pension Benefits			2018 Retiree Health and Life			2017 Retiree Health and Life
Service cost	$	2.2		$	1.7		$	—		$	0.1
Interest cost	3.7			3.9			0.3			0.3
Expected return on plan assets	(5.5		)	(6.0		)	—			—
Settlement expense	—			0.1			—			—
Amortization of (1):
Unrecognized prior service credit	—			—			(0.1		)	(0.1		)
Unrecognized net actuarial loss (gain)	2.6			2.4			—			(0.1		)
Net periodic cost	$	3.0		$	2.1		$	0.2		$	0.2

	2018 Pension Benefits			2017 Pension Benefits			2018 Retiree Health and Life			2017 Retiree Health and Life
Service cost	$	4.1		$	3.3		$	0.1		$	0.1
Interest cost	7.4			7.7			0.5			0.5
Expected return on plan assets	(11.1		)	(12.0		)	—			—
Settlement expense	—			0.1			—			—
Amortization of (1):
Unrecognized prior service credit	—			—			(0.1		)	(0.1		)
Unrecognized net actuarial loss (gain)	5.1			4.7			—			(0.2		)
Net periodic cost	$	5.5		$	3.8		$	0.5		$	0.3