Pension Plans and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2022

Retirement Benefits, Description [Abstract]

Components of Net Periodic Benefit Cost

The Company uses a December 31 measurement date for its defined benefit pension and other postretirement benefit plans. The following table sets forth the components of net periodic benefit costs for the three and nine months ended September 30 (dollars in thousands):

	Pension Benefits						Other Postretirement Benefits
	2022			2021			2022			2021
Three months ended September 30:
Service cost	$	5,914		$	6,412		$	1,095		$	1,062
Interest cost		6,578			6,528			1,343			1,305
Expected return on plan assets		(10,950	)		(9,835	)		(700	)		(509	)
Amortization of prior service cost		75			75			(275	)		(275	)
Net loss recognition		997			1,592			826			777
Net periodic benefit cost	$	2,614		$	4,772		$	2,289		$	2,360
Nine months ended September 30:
Service cost	$	17,914		$	18,912		$	3,255		$	2,967
Interest cost		20,005			19,638			4,167			3,990
Expected return on plan assets		(32,851	)		(29,314	)		(2,100	)		(1,967	)
Amortization of prior service cost		225			225			(825	)		(825	)
Net loss recognition		3,084			5,103			2,586			3,196
Net periodic benefit cost	$	8,377		$	14,564		$	7,083		$	7,361