Retirement Plans

3 Months Ended

Mar. 31, 2017

Compensation and Retirement Disclosure [Abstract]

Retirement Plans

12. Retirement Plans

The net periodic benefit cost for the Company's defined benefit pension plans was as follows:

	Three Months Ended
	March 31, 2017			March 25, 2016
Service cost	$	1.3		$	0.4
Interest cost	1.7			3.5
Expected return on plan assets	(1.3		)	(4.2		)
Amortization of net actuarial loss	2.2			2.6
Amortization of prior service cost	0.1			—
Plan settlements	69.2			3.7
Net periodic benefit cost	$	73.2		$	6.0

The net periodic benefit credit for the Company's postretirement benefit plans was approximately zero for the three months ended March 31, 2017 and $0.1 million for the three months ended March 25, 2016.

Net periodic benefit cost for the Company's defined benefit pension plans and postretirement benefit plans was included within cost of sales; research and development; and selling, general and administrative ("SG&A") expenses on the unaudited condensed consolidated statements of income.

Pension Plan Termination

During the three months ended March 31, 2017, the Company completed the settlement of remaining obligations of six defined benefit pension plans that were terminated during fiscal 2016. In conjunction with this final settlement, the Company made a $61.3 million cash contribution to the terminated plans and recognized a $69.2 million charge, included within SG&A expenses.