Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2023

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 and nine months ended September 30, 2023 and 2022 were as follows:

	Three Months Ended Sep 30,				Nine Months Ended Sep 30,
($ in thousands)	2023		2022		2023		2022
RAP
Service cost	$	800	$	906	$	2,392	$	2,752
Interest cost	2,794		1,820		8,165		5,364
Expected return on plan assets	(8,243)		(6,706)		(24,647)		(20,177)
Amortization of prior service cost	(63)		(63)		(188)		(188)
Amortization of actuarial loss	—		347		37		494
Total net periodic pension cost	$	(4,713)	$	(3,696)	$	(14,241)	$	(11,754)
Postretirement Plan
Interest cost	$	20	$	13	$	59	$	40
Amortization of prior service cost	(19)		(19)		(56)		(56)
Amortization of actuarial (gain)	(7)		—		(22)		—
Total net periodic benefit cost	$	(6)	$	(6)	$	(19)	$	(17)