Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2019

Retirement Benefits [Abstract]

Benefit costs

Pension costs, which primarily include costs for the qualified TRP and the non-qualified SERP, are presented in the following table (in thousands):

	Quarter ended June 30,						Six months ended June 30,
	2019			2018			2019			2018
Service cost-benefits earned during the period	$	—		$	6		$	—		$	6
Interest cost on benefit obligation	5,773			5,074			11,523			10,224
Expected return on plan assets	(6,585		)	(7,480		)	(13,160		)	(14,930		)
Amortization of prior service cost	20			34			45			84
Amortization of actuarial loss	1,541			1,293			3,041			2,543
Pension payment timing related charge	686			—			686			6,300
Expense for company-sponsored retirement plans	$	1,435		$	(1,073	)	$	2,135		$	4,227