Pension Plans and Other Postretirement Benefit Plans (Tables)

6 Months Ended

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

	Pension Benefits						Other Postretirement Benefits
	2020			2019			2020			2019
Three months ended June 30:
Service cost	$	5,550		$	4,948		$	980		$	753
Interest cost		6,967			7,100			1,524			1,164
Expected return on plan assets		(8,625	)		(7,953	)		(590	)		(611	)
Amortization of prior service cost		75			75			(275	)		(275	)
Net loss recognition		1,679			2,426			1,243			1,329
Net periodic benefit cost	$	5,646		$	6,596		$	2,882		$	2,360
Six months ended June 30:
Service cost	$	11,096		$	9,822		$	1,959		$	1,525
Interest cost		13,938			14,238			3,039			2,536
Expected return on plan assets		(17,750	)		(15,768	)		(1,220	)		(1,329	)
Amortization of prior service cost		150			150			(550	)		(550	)
Net loss recognition		3,333			4,841			2,486			2,575
Net periodic benefit cost	$	10,767		$	13,283		$	5,714		$	4,757