Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Net period benefit cost for the pension and postretirement plans

The components of net periodic pension cost and net periodic benefit cost for the RAP and Postretirement Plan for the three months ended March 31, 2021 and 2020 were as follows:

	Three Months Ended March 31,
($ in Thousands)	2021		2020
Components of Net Periodic Benefit Cost
RAP
Service cost	$	2,075	$	2,165
Interest cost	1,623		2,008
Expected return on plan assets	(6,430)		(6,405)
Amortization of prior service cost	(18)		(19)
Amortization of actuarial loss (gain)	1,050		808
Total net periodic pension cost	$	(1,701)	$	(1,444)
Postretirement Plan
Interest cost	$	13	$	20
Amortization of prior service cost	(19)		(19)
Total net periodic benefit cost	$	(6)	$	1