Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2021

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):

	2021		2020
Unfunded benefit obligation for pensions and other postretirement benefit    plans - net of taxes of $2,934 and $3,822, respectively	$	11,039	$	14,378

Reclassification out of Accumulated Other Comprehensive Income

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)	2021			2020			2019
Amortization of defined benefit pension items
Amortization of net prior service cost (a)	$	(793	)	$	(794	)	$	(794	)
Amortization of net loss (a)		38,070			5,586			17,074
Adjustment due to effects of regulation (a)		(33,050	)		(10,006	)		(19,309	)
Total before tax (b)		4,227			(5,214	)		(3,029	)
Tax expense (b)		(888	)		1,095			636
Net of tax (b)	$	3,339		$	(4,119	)	$	(2,393	)

(a)These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 11 for additional details).

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