Retirement Plans and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Cost (Income)

Components of net periodic benefit cost (income) were as follows:

	Three Months Ended June 30,
	2016			2015			2016		2015
(Dollars in thousands)	Retirement Plans						Other Post Retirement Benefits
Service cost	$	170		$	193		$	11	$	14
Interest cost	519			488			33		27
Expected return on plan assets	(753		)	(756		)	—		—
Amortization of net actuarial loss	322			326			7		14
Accretion of prior service cost	(70		)	(70		)	—		—
Net periodic benefit cost	$	188		$	181		$	51	$	55

	Six Months Ended June 30,
	2016			2015			2016		2015
(Dollars in thousands)	Retirement Plans						Other Post Retirement Benefits
Service cost	$	341		$	386		$	23	$	29
Interest cost	1,037			976			66		55
Expected return on plan assets	(1,507		)	(1,512		)	—		—
Amortization of net actuarial loss	645			654			13		27
Accretion of prior service cost	(141		)	(140		)	—		—
Net periodic benefit cost (income)	$	375		$	364		$	102	$	111