Debt

3 Months Ended

Mar. 31, 2024

Debt Disclosure [Abstract]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

The following table provides an estimate of the fair value of long-term debt, including current maturities of long-term debt, using market prices in effect on the valuation date:

	March 31,				December 31,
In thousands	2024		2023		2023
NW Natural:
Gross long-term debt	$	1,374,700	$	1,334,700	$	1,374,700
Unamortized debt issuance costs	(9,801)		(10,278)		(9,968)
Carrying amount	1,364,899		1,324,422		1,364,732
Estimated fair value(1)	1,214,625		1,186,110		1,236,559
NW Holdings:
Gross long-term debt	$	1,586,189	$	1,545,730	$	1,586,344
Unamortized debt issuance costs	(10,585)		(10,428)		(10,044)
Carrying amount	1,575,604		1,535,302		1,576,300
Estimated fair value(1)	1,425,765		1,395,321		1,447,941

(1) Estimated fair value does not include unamortized debt issuance costs.