Retirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2017

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):

	Three Months Ended March 31, 2017
(in thousands)	Hourly Employees’ Pension Plan			Employees’ Retirement Plan				Total
Service cost		$	—		$	1		$	1
Interest cost		—			208			208
Expected return on plan assets		—			(319		)	(319		)
Amortization of net loss		—			108			108
Net periodic benefit		$	—		$	(2	)	$	(2	)

	Three Months Ended March 31, 2016
(in thousands)	Hourly Employees’ Pension Plan				Employees’ Retirement Plan				Total
Service cost		$	2			$	1		$	3
Interest cost		100				222			322
Expected return on plan assets		(162		)		(299		)	(461		)
Amortization of net loss		71				110			181
Net periodic benefit cost		$	11			$	34		$	45