Employee Benefit Plans and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 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 June 30,						Six Months Ended June 30,
	2019			2018			2019			2018
Service cost	$	6.2		$	6.2		$	12.3		$	12.4
Interest cost		11.7			10.6			23.5			21.3
Expected return on plan assets		(13.0	)		(14.2	)		(26.0	)		(28.3	)
Net amortization of unrecognized amounts
Prior service cost		1.6			1.8			3.1			3.4
Actuarial loss		1.7			2.3			3.5			4.6
Net periodic benefit cost	$	8.2		$	6.7		$	16.4		$	13.4