Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2016

Retirement Plans

Defined Benefit Plan Disclosure [Line Items]

Benefit costs

Our pension costs, which include costs for qualified TRP plan and nonqualified SERP plan, are presented in the following table (in thousands):

	Quarters Ended						Nine Months Ended
	Sept. 30, 2016			Sept. 27, 2015			Sept. 30, 2016			Sept. 27, 2015
Service cost-benefits earned during the period	$	204		$	97		$	612		$	562
Interest cost on benefit obligation	6,449			5,898			19,636			17,201
Expected return on plan assets (a)	(6,691		)	(8,169		)	(20,073		)	(23,164		)
Amortization of prior service cost	165			206			505			502
Amortization of actuarial loss	1,846			3,652			5,740			6,587
Expense for company-sponsored retirement plans	$	1,973		$	1,684		$	6,420		$	1,688

(a) At the beginning of 2016, we updated our expected annual long-term rate of return on our TRP plan assets to 7.0% from 8.0%. This change resulted in incremental pension costs of approximately $1.4 million in the third quarter of 2016 and approximately $4.2 million of incremental pension costs for the nine months ended September 30, 2016.