Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2018

Retirement Benefits [Abstract]

Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans

The following table sets forth the net periodic benefit cost recognized for the plans:

	Three months ended March 31,
	2018			2017
(in thousands)
Net pension cost included the following components:
Service cost-benefits earned during the period	$	243		$	235
Interest cost on projected benefit obligation		237			249
Amortization of net obligation at transition		1			1
Amortization of prior service cost		(13	)		(3	)
Recognized net actuarial loss		127			96
Net periodic pension cost	$	595		$	578