Pension Benefits and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2020

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

The components of net periodic benefit (credit) cost were as follows:

	Pension Benefits								Other Postretirement Benefits
	Three Months Ended				Nine Months Ended				Three Months Ended				Nine Months Ended
	September 30,				September 30,				September 30,				September 30,
(Dollars in thousands)	2020		2019		2020		2019		2020		2019		2020		2019
Service cost	$	—	$	—	$	—	$	—	$	17	$	12	$	51	$	48
Interest cost	223		1,790		685		5,359		10		14		30		44
Expected return of plan assets	(394)		(2,187)		(1,180)		(6,571)		—		—		—		—
Amortization of prior service credit	—		—		—		—		(28)		(252)		(84)		(758)
Amortization of net loss	99		476		327		1,386		—		—		—		—
Settlement benefit	—		—		(63)		—		—		—		—		—
Net periodic benefit (credit) cost	$	(72)	$	79	$	(231)	$	174	$	(1)	$	(226)	$	(3)	$	(666)