Pension Plans and Other Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 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 six months ended June 30 (dollars in thousands):

	Pension Benefits						Other Postretirement Benefits
	2022			2021			2022			2021
Three months ended June 30:
Service cost	$	6,229		$	6,254		$	1,097		$	897
Interest cost		6,520			6,530			1,384			1,309
Expected return on plan assets		(10,950	)		(9,704	)		(700	)		(783	)
Amortization of prior service cost		75			75			(275	)		(275	)
Net loss recognition		939			1,688			870			1,246
Net periodic benefit cost	$	2,813		$	4,843		$	2,376		$	2,394
Six months ended June 30:
Service cost	$	12,000		$	12,500		$	2,160		$	1,905
Interest cost		13,427			13,110			2,824			2,685
Expected return on plan assets		(21,901	)		(19,479	)		(1,400	)		(1,458	)
Amortization of prior service cost		150			150			(550	)		(550	)
Net loss recognition		2,087			3,511			1,760			2,419
Net periodic benefit cost	$	5,763		$	9,792		$	4,794		$	5,001