Pension Benefits and Other Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 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				Six Months Ended				Three Months Ended				Six Months Ended
	June 30,				June 30,				June 30,				June 30,
(Dollars in thousands)	2020		2019		2020		2019		2020		2019		2020		2019
Service cost	$	—	$	—	$	—	$	—	$	17	$	18	$	34	$	36
Interest cost	231		1,785		462		3,569		10		15		20		30
Expected return of plan assets	(393)		(2,192)		(786)		(4,384)		—		—		—		—
Amortization of prior service credit	—		—		—		—		(28)		(253)		(56)		(506)
Amortization of net loss	114		456		228		910		—		—		—		—
Settlement benefit	(63)		—		(63)		—		—		—		—		—
Net periodic benefit (credit) cost	$	(111)	$	49	$	(159)	$	95	$	(1)	$	(220)	$	(2)	$	(440)