10. Pension Plans

The company has both tax-qualified and nonqualified, noncontributory defined benefit pension plans, that together cover certain domestic and foreign employees. These plans provide benefits based upon a participant’s compensation and years of service.

In the third quarter of 2017, the defined benefit pension plan in the United Kingdom was frozen as to further benefit accruals. This action required a remeasurement of the plans’ assets and obligations, which resulted in a non-cash curtailment gain of $1.7 million. Retirement benefits for future periods for defined benefit plan members who are employed by the company will be provided through an existing defined contribution plan.

The components of net periodic pension cost are as follows:


	Quarter Ended September 30,						Nine Months Ended September 30,
	2017			2016			2017			2016
(dollars in millions)
Service cost, net of employee contributions	$	6.8		$	7.5		$	20.1		$	22.0
Interest cost		4.8			4.8			14.4			14.2
Expected return on plan assets		(8.3	)		(8.0	)		(24.8	)		(24.2	)
Amortization		3.3			2.6			9.8			7.8
Curtailment		(1.7	)		—			(1.7	)		—

Net periodic pension cost	$	4.9		$	6.9		$	17.8		$	19.8