Employee Benefit Plans and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2020

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 September 30,						Nine Months Ended September 30,
	2020			2019			2020			2019
Service cost	$	5.4		$	6.1		$	17.3		$	18.4
Interest cost		9.9			11.7			29.8			35.2
Expected return on plan assets		(14.2	)		(13.0	)		(42.6	)		(39.1	)
Net amortization of unrecognized amounts
Prior service cost		1.1			1.6			3.3			4.7
Actuarial loss		2.7			1.7			8.1			5.3
Net periodic benefit cost	$	4.9		$	8.1		$	15.9		$	24.5