Components of Net Periodic Benefit Cost (Tables)

6 Months Ended

Jun. 30, 2021

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

	Three Months Ended June 30,								Six Months Ended June 30,
(Dollar amounts in thousands)	Pension Benefits				Post-Retirement Health Benefits				Pension Benefits				Post-Retirement Health Benefits
	2021		2020		2021		2020		2021		2020		2021		2020
Service cost	$	338	$	325	$	11	$	9	$	677	$	650	$	22	$	19
Interest cost	658		779		25		31		1,316		1,558		51		62
Expected return on plan assets	(1,179)		(1,049)		—		—		(2,357)		(2,099)		—		—
Net amortization of prior service cost	—		—		—		—		—		—		—		—
Net amortization of net (gain) loss	518		492		—		—		1,036		984		—		—
Net Periodic Benefit Cost	$	335	$	547	$	36	$	40	$	672	$	1,093	$	73	$	81