Debt

9 Months Ended

Sep. 30, 2023

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:

	September 30,				December 31,
In thousands	2023		2022		2022
NW Natural:
Gross long-term debt	$	1,414,700	$	1,134,700	$	1,134,700
Unamortized debt issuance costs	(10,147)		(8,229)		(8,823)
Carrying amount	$	1,404,553	$	1,126,471	$	1,125,877
Estimated fair value(1)	$	1,176,212	$	927,372	$	944,383
NW Holdings:
Gross long-term debt	$	1,625,545	$	1,345,968	$	1,345,851
Unamortized debt issuance costs	(10,245)		(8,348)		(8,987)
Carrying amount	$	1,615,300	$	1,337,620	$	1,336,864
Estimated fair value(1)	$	1,385,144	$	1,133,087	$	1,148,395

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