Employee Benefit Plans and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2019

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Costs

The components of net periodic benefit cost for our pension plans were as follows (dollars in millions):

	Pension Plans
	Three Months Ended March 31,
	2019			2018
Service cost	$	6.2		$	6.2
Interest cost		11.7			10.6
Expected return on plan assets		(13.0	)		(14.2	)
Net amortization of unrecognized amounts
Prior service cost		1.6			1.8
Actuarial loss		1.7			2.3
Net periodic benefit cost	$	8.2		$	6.7