Pension Plans and Other Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2023

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 months ended March 31 (dollars in thousands):

	Pension Benefits						Other Postretirement Benefits
	2023			2022			2023			2022
Three months ended March 31:
Service cost	$	4,894		$	5,771		$	818		$	1,063
Interest cost		7,232			6,907			1,044			1,440
Expected return on plan assets		(10,922	)		(10,951	)		(891	)		(700	)
Amortization of prior service cost		123			75			(263	)		(275	)
Net loss recognition		839			1,148			533			890
Net periodic benefit cost	$	2,166		$	2,950		$	1,241		$	2,418