Retirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Cost

The following tables present the components of net periodic benefit cost (gains are denoted with parentheses and losses are not):

	Nine Months Ended September 30, 2016
(in thousands)	Hourly Employees’ Pension Plan				Employees’ Retirement Plan				Total
Service cost		$	6			$	3		$	9
Interest cost		300				666			966
Expected return on plan assets		(486		)		(898		)	(1,384		)
Amortization of net loss		213				330			543
Net periodic benefit cost		$	33			$	101		$	134

	Nine Months Ended September 30, 2015
(in thousands)	Hourly Employees’ Pension Plan				Employees’ Retirement Plan				Total
Service cost		$	6			$	3		$	9
Interest cost		303				651			954
Expected return on plan assets		(495		)		(921		)	(1,416		)
Amortization of net loss		186				300			486
Net periodic benefit cost		$	—			$	33		$	33