Components of Net Periodic Benefit Cost (Tables)

9 Months Ended

Sep. 30, 2021

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

	Three Months Ended September 30,								Nine Months Ended September 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	$	339	$	325	$	10	$	10	$	1,016	$	975	$	32	$	29
Interest cost	658		779		26		32		1,974		2,337		77		94
Expected return on plan assets	(1,178)		(1,050)		—		—		(3,535)		(3,149)		—		—
Net amortization of prior service cost	—		1		—		—		—		1		—		—
Net amortization of net (gain) loss	518		492		—		—		1,554		1,476		—		—
Net Periodic Benefit Cost	$	337	$	547	$	36	$	42	$	1,009	$	1,640	$	109	$	123