Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2016

Retirement Plans

Defined Benefit Plan Disclosure [Line Items]

Benefit costs

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

	Quarters Ended						Six Months Ended
	June 30, 2016			June 28, 2015			June 30, 2016			June 28, 2015
Service cost-benefits earned during the period	$	158		$	232		$	408		$	465
Interest cost on benefit obligation	6,837			5,651			13,187			11,303
Expected return on plan assets (a)	(6,632		)	(7,498		)	(13,382		)	(14,995		)
Amortization of prior service cost	190			148			340			296
Amortization of actuarial loss	2,194			1,467			3,894			2,935
Expense for company-sponsored retirement plans	$	2,747		$	—		$	4,447		$	4

(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 second quarter of 2016 and approximately $2.8 of incremental pension costs for the six months ended June 30, 2016.