Pension Plans

3 Months Ended

Mar. 31, 2016

Pension Plans

9. 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.

The components of net periodic pension cost are as follows:

	Three Months Ended March 31,
	2016			2015
(dollars in millions)
Service cost, net of employee contributions	$	7.3		$	7.5
Interest cost		4.7			5.0
Expected return on plan assets		(8.1	)		(7.8	)
Amortization		2.6			2.9
Net periodic pension cost	$	6.5		$	7.6

In 2016, the company changed its method used to estimate the service and interest cost components of net periodic benefit cost for defined benefit plans from a single weighted-average discount rate to a full yield curve approach. The reduction in service and interest cost for the quarter ended March 31, 2016 associated with this change in estimate was approximately $1.3 million.