Pension Plans and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2020

General Discussion Of Pension And Other Postretirement Benefits [Abstract]

Components of Net Periodic Benefit Costs

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
	2020			2019			2020			2019
Three months ended September 30:
Service cost	$	5,549		$	4,948		$	982		$	754
Interest cost		6,968			7,134			1,524			1,140
Expected return on plan assets		(8,625	)		(7,913	)		(590	)		(616	)
Amortization of prior service cost		75			75			(275	)		(275	)
Net loss recognition		1,678			2,553			1,243			1,299
Net periodic benefit cost	$	5,645		$	6,797		$	2,884		$	2,302
Nine months ended September 30:
Service cost	$	16,645		$	14,770		$	2,941		$	2,279
Interest cost		20,906			21,372			4,563			3,676
Expected return on plan assets		(26,375	)		(23,681	)		(1,810	)		(1,945	)
Amortization of prior service cost		225			225			(825	)		(825	)
Net loss recognition		5,011			7,394			3,729			3,874
Net periodic benefit cost	$	16,412		$	20,080		$	8,598		$	7,059