Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Schedule of Regulatory Assets

Amounts NW Natural deferred as regulatory assets and liabilities were as follows:

	Regulatory Assets
In thousands	2022		2021
NW Natural:
Current:
Unrealized loss on derivatives(1)	$	28,728	$	10,402
Gas costs	61,223		35,641
Environmental costs(2)	7,392		6,694
Decoupling(3)	—		969
Pension balancing(4)	7,131		7,131
Income taxes	2,208		2,568
Other(5)	10,809		8,986
Total current	$	117,491	$	72,391
Non-current:
Unrealized loss on derivatives(1)	$	20,838	$	412
Pension balancing(4)	32,997		38,302
Income taxes	10,943		12,609
Pension and other postretirement benefit liabilities	101,413		116,440
Environmental costs(2)	104,253		94,636
Gas costs	22,355		15,477
Other(5)	47,608		36,663
Total non-current	$	340,407	$	314,539
Other (NW Holdings)	25		40
Total non-current -NW Holdings	$	340,432	$	314,579

Schedule of Regulatory Liabilities

	Regulatory Liabilities
In thousands	2022		2021
NW Natural:
Current:
Gas costs	$	4,121	$	70
Unrealized gain on derivatives(1)	194,236		48,130
Decoupling(3)	14,026		4,475
Income taxes(6)	7,166		8,192
Asset optimization revenue sharing	26,368		45,124
Other(5)	2,636		6,290
Total current - NW Natural	$	248,553	$	112,281
Other (NW Holdings)	29		—
Total current - NW Holdings	$	248,582	$	112,281
Non-current:
Gas costs	$	12,644	$	250
Unrealized gain on derivatives(1)	5,045		10,730
Decoupling(3)	3,814		3,412
Income taxes(6)	174,212		181,404
Accrued asset removal costs(7)	467,742		445,952
Asset optimization revenue sharing	8,401		1,810
Other(5)	16,741		13,792
Total non-current - NW Natural	$	688,599	$	657,350
Other (NW Holdings)	979		982
Total non-current -NW Holdings	$	689,578	$	658,332

(1)Unrealized gains or losses on derivatives are non-cash items and, therefore, do not earn a rate of return or a carrying charge. These amounts are recoverable through natural gas distribution rates as part of the annual Purchased Gas Adjustment (PGA) mechanism when realized at settlement.

(2)Refer to the Environmental Cost Deferral and Recovery table in Note 17 for a description of environmental costs.

(3)This deferral represents the margin adjustment resulting from differences between actual and expected volumes. 

(4)Refer to Note 10 for information regarding the deferral of pension expenses.

(5)Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge.

(6)This balance represents estimated amounts associated with the Tax Cuts and Jobs Act. See Note 11.

(7)Estimated costs of removal on certain regulated properties are collected through rates. See "Accounting Policies—Plant, Property, and Accrued Asset Removal Costs" below.

Accounts Receivable, Allowance for Credit Loss

The following table presents the activity related to the NW Holdings provision for uncollectible accounts by pool, substantially all of which is related to NW Natural's accounts receivable:

	As of December 31, 2021						As of December 31, 2022
			Year ended December 31, 2022
In thousands	Beginning Balance		Provision recorded, net of adjustments		Write-offs recognized, net of recoveries		Ending Balance
Allowance for uncollectible accounts:
Residential	$	1,460	$	1,974	$	(1,062)	$	2,372
Commercial	178		546		(324)		400
Industrial	67		186		(65)		188
Accrued unbilled and other	313		185		(162)		336
Total	$	2,018	$	2,891	$	(1,613)	$	3,296