Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2023

Accumulated Other Comprehensive Loss [Abstract]

Schedule of Accumulated Other Comprehensive Loss, Net of Tax

Accumulated other comprehensive loss, net of tax, consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Unfunded benefit obligation for pensions and other postretirement benefit    plans - net of taxes of $95 and $547, respectively	$	357	$	2,058

Reclassification out of Accumulated Other Comprehensive Loss

The following table details the reclassifications out of accumulated other comprehensive loss by component for the years ended December 31 (dollars in thousands):

	Amounts Reclassified from Accumulated Other Comprehensive Loss
Details about Accumulated Other Comprehensive Loss Components (Affected Line Item in Statements of Income)	2023			2022			2021
Amortization of defined benefit pension and postretirement benefit items
Amortization of net prior service cost (a)	$	(558	)	$	(4,095	)	$	(793	)
Amortization of net loss (a)		18,872			57,650			38,070
Adjustment due to effects of regulation (a)		(16,161	)		(42,187	)		(33,050	)
Total before tax (b)		2,153			11,368			4,227
Tax expense (b)		(452	)		(2,387	)		(888	)
Net of tax (b)	$	1,701		$	8,981		$	3,339

(a)These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 12 for additional details).

(b)Description is also the affected line item on the Consolidated Statements of Income.