Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2024

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, 2024 and 2023 were as follows:

	Three Months Ended Mar 31,
($ in thousands)	2024		2023
RAP
Service cost	$	874	$	796
Interest cost	2,719		2,686
Expected return on plan assets	(8,650)		(8,202)
Amortization of prior service cost	(53)		(63)
Amortization of actuarial loss	—		37
Total net periodic pension cost	$	(5,111)	$	(4,746)
Postretirement Plan
Interest cost	$	18	$	20
Amortization of prior service cost	(19)		(19)
Amortization of actuarial (gain)	(7)		(7)
Total net periodic benefit cost	$	(8)	$	(7)