Northwest Natural Holding (NWN) 10-Q 4 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 28, 2022
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2022
Entity Registrant Name	NORTHWEST NATURAL HOLDING COMPANY
Entity File Number	1-38681
Entity Incorporation, State or Country Code	OR
Entity Tax Identification Number	82-4710680
Entity Address, Address Line One	250 SW Taylor Street
Entity Address, City or Town	Portland
Entity Address, State or Province	OR
Entity Address, Postal Zip Code	97204
City Area Code	(503)
Local Phone Number	226-4211
Title of 12(b) Security	Common Stock
Trading Symbol	NWN
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		34,817,043
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Central Index Key	0001733998
Northwest Natural Gas Company [Member]
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jun. 30, 2022
Entity Registrant Name	NORTHWEST NATURAL GAS COMPANY
Entity File Number	1-15973
Entity Incorporation, State or Country Code	OR
Entity Tax Identification Number	93-0256722
Entity Address, Address Line One	250 SW Taylor Street
Entity Address, City or Town	Portland
Entity Address, State or Province	OR
Entity Address, Postal Zip Code	97204
City Area Code	(503)
Local Phone Number	226-4211
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Central Index Key	0000073020

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating revenues [Abstract]
Operating revenues	$ 194,960	$ 148,917	$ 545,261	$ 464,863
Operating expenses:
Cost of gas	79,720	41,193	225,308	153,403
Operations and maintenance	53,175	50,047	110,660	102,238
Environmental remediation	2,267	1,509	6,970	5,286
General taxes	8,989	8,914	21,093	20,283
Revenue taxes	8,240	5,671	21,600	18,335
Depreciation	28,110	28,144	56,539	56,241
Other operating expenses	920	815	1,914	1,747
Total operating expenses	181,421	136,293	444,084	357,533
Income from operations	13,539	12,624	101,177	107,330
Other income (expense), net	226	(2,597)	(728)	(6,139)
Interest expense, net	11,580	11,028	23,102	22,154
Income (loss) before income taxes	2,185	(1,001)	77,347	79,037
Income tax expense (benefit)	470	(277)	19,393	20,244
Net income (loss)	1,715	(724)	57,954	58,793
Other comprehensive income:
Amortization of non-qualified employee benefit plan liability, net of taxes	197	221	394	442
Comprehensive income (loss)	1,912	(503)	58,348	59,235
Supplemental Income Statement Elements [Abstract]
Amortization of non-qualified employee benefit plan liability, tax	$ 71	$ 80	$ 142	$ 160
Average common shares outstanding:
Basic (in shares)	34,307	30,664	32,756	30,639
Diluted (in shares)	34,352	30,664	32,805	30,671
Earnings per share of common stock:
Basic (in dollars per share)	$ 0.05	$ (0.02)	$ 1.77	$ 1.92
Diluted (in dollars per share)	$ 0.05	$ (0.02)	$ 1.77	$ 1.92
Northwest Natural Gas Company [Member]
Operating revenues [Abstract]
Operating revenues	$ 190,251	$ 144,579	$ 536,875	$ 456,929
Operating expenses:
Cost of gas	79,776	41,249	225,420	153,515
Operations and maintenance	48,879	44,939	102,756	94,126
Environmental remediation	2,267	1,509	6,970	5,286
General taxes	8,872	8,783	20,861	20,042
Revenue taxes	8,208	5,650	21,532	18,305
Depreciation	27,328	27,530	54,965	54,699
Other operating expenses	796	780	1,695	1,699
Total operating expenses	176,126	130,440	434,199	347,672
Income from operations	14,125	14,139	102,676	109,257
Other income (expense), net	17	(2,566)	(964)	(6,231)
Interest expense, net	10,599	10,696	21,430	21,486
Income (loss) before income taxes	3,543	877	80,282	81,540
Income tax expense (benefit)	810	288	20,133	20,840
Net income (loss)	2,733	589	60,149	60,700
Other comprehensive income:
Amortization of non-qualified employee benefit plan liability, net of taxes	197	221	394	442
Comprehensive income (loss)	2,930	810	60,543	61,142
Supplemental Income Statement Elements [Abstract]
Amortization of non-qualified employee benefit plan liability, tax	$ 71	$ 80	$ 142	$ 160

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Current assets:
Cash and cash equivalents	$ 17,209	$ 18,559	$ 20,084
Accounts receivable	68,583	101,495	60,713
Accrued unbilled revenue	18,060	82,169	13,592
Allowance for uncollectible accounts	(1,356)	(2,018)	(3,283)
Regulatory assets	92,803	72,391	60,672
Derivative instruments	60,652	48,130	46,168
Inventories	65,983	57,262	39,024
Income taxes receivable	0	0	6,000
Other current assets	36,060	59,288	30,871
Total current assets	357,994	437,276	273,841
Non-current assets:
Property, plant, and equipment	4,129,236	3,997,243	3,849,792
Less: Accumulated depreciation	1,150,555	1,125,873	1,093,863
Total property, plant, and equipment, net	2,978,681	2,871,370	2,755,929
Regulatory assets	301,855	314,579	330,710
Derivative instruments	9,121	10,730	7,912
Other investments	96,027	89,278	77,577
Operating lease right of use asset, net	73,754	75,049	76,294
Assets under sales-type leases	136,673	138,995	141,408
Goodwill	70,714	70,570	69,313
Other non-current assets	75,699	56,757	50,516
Total non-current assets	3,742,524	3,627,328	3,509,659
Total assets	4,100,518	4,064,604	3,783,500
Current liabilities:
Short-term debt	222,700	389,500	240,000
Current maturities of long-term debt	351	345	60,274
Accounts payable	135,364	133,486	97,854
Taxes accrued	11,324	15,520	15,143
Interest accrued	7,425	7,503	7,425
Regulatory liabilities	97,277	112,281	103,210
Derivative instruments	15,918	10,402	3,393
Operating lease liabilities	1,315	1,296	1,228
Other current liabilities	47,624	54,432	43,946
Total current liabilities	539,298	724,765	572,473
Long-term debt	1,045,530	1,044,587	915,501
Deferred credits and other non-current liabilities:
Deferred tax liabilities	355,470	340,231	325,600
Regulatory liabilities	658,925	658,332	645,046
Pension and other postretirement benefit liabilities	162,511	166,684	203,854
Derivative instruments	9,475	412	453
Operating lease liabilities	78,826	79,468	80,088
Other non-current liabilities	111,704	114,979	117,659
Total deferred credits and other non-current liabilities	1,376,911	1,360,106	1,372,700
Commitments and contingencies (Note 16)
Equity:
Common stock	$ 767,826	$ 590,771	$ 569,785
Shares Authorized (in shares)	100,000,000	100,000,000	100,000,000
Shares outstanding (in shares)	34,754,000	31,129,000	30,672,000
Shares issued (in shares)	34,754,000	31,129,000	30,672,000
Par Value (in dollars per share)	$ 0	$ 0	$ 0
Retained earnings	$ 381,963	$ 355,779	$ 365,501
Accumulated other comprehensive loss	(11,010)	(11,404)	(12,460)
Total equity	1,138,779	935,146	922,826
Total liabilities and equity	4,100,518	4,064,604	3,783,500
Northwest Natural Gas Company [Member]
Current assets:
Cash and cash equivalents	10,267	12,271	11,488
Accounts receivable	66,186	99,780	51,849
Accrued unbilled revenue	17,840	82,028	13,474
Receivables from affiliates	300	261	301
Allowance for uncollectible accounts	(1,299)	(1,962)	(3,239)
Regulatory assets	92,803	72,391	60,672
Derivative instruments	60,652	48,130	46,168
Inventories	64,726	56,752	38,549
Other current assets	31,784	47,378	30,630
Total current assets	343,259	417,029	249,892
Non-current assets:
Property, plant, and equipment	4,052,467	3,931,640	3,794,870
Less: Accumulated depreciation	1,142,611	1,119,361	1,088,743
Total property, plant, and equipment, net	2,909,856	2,812,279	2,706,127
Regulatory assets	301,790	314,539	330,670
Derivative instruments	9,121	10,730	7,912
Other investments	81,486	74,786	77,547
Operating lease right of use asset, net	73,706	74,987	76,211
Assets under sales-type leases	136,673	138,995	141,408
Other non-current assets	74,106	55,027	49,665
Total non-current assets	3,586,738	3,481,343	3,389,540
Total assets	3,929,997	3,898,372	3,639,432
Current liabilities:
Short-term debt	78,700	245,500	198,000
Current maturities of long-term debt	0	0	59,987
Accounts payable	132,002	131,475	95,109
Payables to affiliates	7,259	1,248	22,869
Taxes accrued	11,289	15,476	10,072
Interest accrued	7,207	7,296	7,373
Regulatory liabilities	97,277	112,281	103,210
Derivative instruments	15,918	10,402	3,393
Operating lease liabilities	1,298	1,273	1,193
Other current liabilities	46,816	53,591	43,389
Total current liabilities	397,766	578,542	544,595
Long-term debt	986,762	986,495	857,422
Deferred credits and other non-current liabilities:
Deferred tax liabilities	352,606	337,717	323,522
Regulatory liabilities	657,943	657,350	644,177
Pension and other postretirement benefit liabilities	162,511	166,684	203,854
Derivative instruments	9,475	412	453
Operating lease liabilities	78,789	79,431	80,043
Other non-current liabilities	110,469	113,934	116,975
Total deferred credits and other non-current liabilities	1,371,793	1,355,528	1,369,024
Commitments and contingencies (Note 16)
Equity:
Common stock	601,032	435,515	319,506
Retained earnings	583,654	553,696	561,345
Accumulated other comprehensive loss	(11,010)	(11,404)	(12,460)
Total equity	1,173,676	977,807	868,391
Total liabilities and equity	$ 3,929,997	$ 3,898,372	$ 3,639,432

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands	Total	Northwest Natural Gas Company [Member]	Common Stock Including APIC [Member]	Common Stock Including APIC [Member] Northwest Natural Gas Company [Member]	Retained Earnings [Member]	Retained Earnings [Member] Northwest Natural Gas Company [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Northwest Natural Gas Company [Member]
Beginning Balance at Dec. 31, 2020	$ 888,733	$ 835,184	$ 565,112	$ 319,506	$ 336,523	$ 528,580	$ (12,902)	$ (12,902)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent		0		0
Net income	58,793	60,700			58,793	60,700
Dividends on common stock					(29,815)	(27,935)
Other comprehensive income	59,235	61,142					442	442
Stock-based compensation			2,446
Shares issued pursuant to equity based plans, net of shares withheld for taxes			2,227
Issuances of common stock, net of issuance costs			0
Ending Balance at Jun. 30, 2021	$ 922,826	868,391	569,785	319,506	365,501	561,345	(12,460)	(12,460)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per share of common stock	$ 0.9600
Beginning Balance at Mar. 31, 2021	$ 936,324	881,565	568,066	319,506	380,939	574,740	(12,681)	(12,681)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent				0
Net income	(724)	589			(724)	589
Dividends on common stock					(14,714)	(13,984)
Other comprehensive income	(503)	810					221	221
Stock-based compensation			416
Shares issued pursuant to equity based plans, net of shares withheld for taxes			1,303
Issuances of common stock, net of issuance costs			0
Ending Balance at Jun. 30, 2021	$ 922,826	868,391	569,785	319,506	365,501	561,345	(12,460)	(12,460)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per share of common stock	$ 0.4800
Beginning Balance at Dec. 31, 2021	$ 935,146	977,807	590,771	435,515	355,779	553,696	(11,404)	(11,404)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent		165,517		165,517
Net income	57,954	60,149			57,954	60,149
Dividends on common stock					(31,770)	(30,191)
Other comprehensive income	58,348	60,543					394	394
Stock-based compensation			2,232
Shares issued pursuant to equity based plans, net of shares withheld for taxes			1,004
Issuances of common stock, net of issuance costs			173,819
Ending Balance at Jun. 30, 2022	$ 1,138,779	1,173,676	767,826	601,032	381,963	583,654	(11,010)	(11,010)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per share of common stock	$ 0.9650
Beginning Balance at Mar. 31, 2022	$ 987,944	1,021,609	602,382	436,042	396,769	596,774	(11,207)	(11,207)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent				164,990
Net income	1,715	2,733			1,715	2,733
Dividends on common stock					(16,521)	(15,853)
Other comprehensive income	1,912	2,930					197	197
Stock-based compensation			458
Shares issued pursuant to equity based plans, net of shares withheld for taxes			1,080
Issuances of common stock, net of issuance costs			163,906
Ending Balance at Jun. 30, 2022	$ 1,138,779	$ 1,173,676	$ 767,826	$ 601,032	$ 381,963	$ 583,654	$ (11,010)	$ (11,010)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per share of common stock	$ 0.4825

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities:
Net income	$ 57,954	$ 58,793
Adjustments to reconcile net income to cash provided by operations:
Depreciation	56,539	56,241
Regulatory amortization of gas reserves	2,984	7,597
Deferred income taxes	10,659	1,048
Qualified defined benefit pension plan expense	2,882	7,874
Contributions to qualified defined benefit pension plans	0	(9,590)
Deferred environmental expenditures, net	(9,608)	(9,625)
Environmental remediation expense	6,970	5,286
Other	9,961	10,663
Changes in assets and liabilities:
Receivables, net	96,453	73,133
Inventories	(8,721)	3,666
Income and other taxes	17,241	21,467
Accounts payable	(13,728)	(17,239)
Deferred gas costs	2,607	(26,962)
Asset optimization revenue sharing	3,929	36,872
Decoupling mechanism	9,669	(6,860)
Other, net	(8,125)	(9,030)
Cash provided by operating activities	196,564	194,281
Investing activities:
Capital expenditures	(167,696)	(130,108)
Acquisitions, net of cash acquired	0	(55)
Proceeds from the sale of assets	345	2,234
Other	(2,336)	46
Cash used in investing activities	(169,687)	(127,883)
Financing activities:
Proceeds from common stock issued, net	174,053	0
Long-term debt issued	692	55,000
Long-term debt retired	0	(35,000)
Proceeds from term loan due within one year	0	100,000
Repayment of commercial paper, maturities greater than three months	0	(195,025)
Changes in other short-term debt, net	(166,800)	30,500
Cash dividend payments on common stock	(30,311)	(27,842)
Other	(1,596)	(1,175)
Cash used in financing activities	(23,962)	(73,542)
Cash, cash equivalents and restricted cash	30,035	28,310
Increase (decrease) in cash, cash equivalents and restricted cash	2,915	(7,144)
Supplemental disclosure of cash flow information:
Interest paid, net of capitalization	22,867	21,971
Income taxes paid, net of refunds	1,086	7,405
Northwest Natural Gas Company [Member]
Operating activities:
Net income	60,149	60,700
Adjustments to reconcile net income to cash provided by operations:
Depreciation	54,965	54,699
Regulatory amortization of gas reserves	2,984	7,597
Deferred income taxes	10,308	201
Qualified defined benefit pension plan expense	2,882	7,874
Contributions to qualified defined benefit pension plans	0	(9,590)
Deferred environmental expenditures, net	(9,608)	(9,625)
Environmental remediation expense	6,970	5,286
Asset optimization revenue sharing bill credits	(41,102)	(9,053)
Other	9,158	9,534
Changes in assets and liabilities:
Receivables, net	97,175	74,354
Inventories	(7,974)	3,775
Income and other taxes	16,069	19,440
Accounts payable	(16,341)	(19,936)
Deferred gas costs	2,607	(26,962)
Asset optimization revenue sharing	3,929	36,872
Decoupling mechanism	9,669	(6,860)
Other, net	(8,404)	(8,361)
Cash provided by operating activities	193,436	189,945
Investing activities:
Capital expenditures	(156,189)	(125,167)
Proceeds from the sale of assets	345	2,234
Other	(2,336)	46
Cash used in investing activities	(158,180)	(122,887)
Financing activities:
Capital contributions from parent	165,517	0
Proceeds from term loan due within one year	0	100,000
Repayment of commercial paper, maturities greater than three months	0	(195,025)
Changes in other short-term debt, net	(166,800)	61,500
Cash dividend payments on common stock	(30,191)	(27,935)
Other	(1,521)	(1,623)
Cash used in financing activities	(32,995)	(63,083)
Cash, cash equivalents and restricted cash	23,093	19,714
Increase (decrease) in cash, cash equivalents and restricted cash	2,261	3,975
Supplemental disclosure of cash flow information:
Interest paid, net of capitalization	21,270	21,285
Income taxes paid, net of refunds	$ 3,490	$ 10,910

Organization and Principles of

Organization and Principles of Consolidation	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Principles of Consolidation	ORGANIZATION AND PRINCIPLES OF CONSOLIDATION The accompanying consolidated financial statements represent the respective, consolidated financial results of Northwest Natural Holding Company (NW Holdings) and Northwest Natural Gas Company (NW Natural) and all respective companies that each registrant directly or indirectly controls, either through majority ownership or otherwise. This is a combined report of NW Holdings and NW Natural, which includes separate consolidated financial statements for each registrant. NW Natural's regulated natural gas distribution activities are reported in the natural gas distribution (NGD) segment. The NGD segment is NW Natural's core operating business and serves residential, commercial, and industrial customers in Oregon and southwest Washington. The NGD segment is the only reportable segment for NW Holdings and NW Natural. All other activities, water businesses, and other investments are aggregated and reported as other at their respective registrant. NW Holdings and NW Natural consolidate all entities in which they have a controlling financial interest. Investments in corporate joint ventures and partnerships that NW Holdings does not directly or indirectly control, and for which it is not the primary beneficiary, include NNG Financial's investment in Kelso-Beaver Pipeline and NWN Water's investment in Avion Water Company, Inc., which are accounted for under the equity method. NW Natural RNG Holding Company, LLC holds an investment in Lexington Renewable Energy, LLC, which is also accounted for under the equity method. See Note 13 for activity related to equity method investments. NW Holdings and its direct and indirect subsidiaries are collectively referred to herein as NW Holdings, and NW Natural and its direct and indirect subsidiaries are collectively referred to herein as NW Natural. The consolidated financial statements of NW Holdings and NW Natural are presented after elimination of all intercompany balances and transactions. Information presented in these interim consolidated financial statements is unaudited, but includes all material adjustments management considers necessary for a fair statement of the results for each period reported including normal recurring accruals. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in NW Holdings' and NW Natural's combined 2021 Annual Report on Form 10-K (2021 Form 10-K). A significant part of NW Holdings' and NW Natural's business is of a seasonal nature; therefore, NW Holdings and NW Natural results of operations for interim periods are not necessarily indicative of full year results. Seasonality affects the comparability of the results of other operations across quarters but not across years. Notes to the consolidated financial statements reflect the activity for both NW Holdings and NW Natural for all periods presented, unless otherwise noted. Certain reclassifications have been made to conform prior period information to the current presentation. The reclassifications did not have a material effect on our consolidated financial statements.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Significant accounting policies are described in Note 2 of the 2021 Form 10-K. There were no material changes to those accounting policies during the six months ended June 30, 2022 other than those set forth in this Note 2. The following are current updates to certain critical accounting policy estimates and new accounting standards. Industry Regulation In applying regulatory accounting principles, NW Holdings and NW Natural capitalize or defer certain costs and revenues as regulatory assets and liabilities pursuant to orders of the Oregon Public Utilities Commission (OPUC), Washington Utilities and Transportation Commission (WUTC), Idaho Public Utilities Commission (IPUC) or Public Utility Commission of Texas (PUCT), as applicable, which provide for the recovery of revenues or expenses from, or refunds to, utility customers in future periods, including a return or a carrying charge in certain cases. Amounts deferred as regulatory assets and liabilities for NW Holdings and NW Natural were as follows: Regulatory Assets June 30, December 31, In thousands 2022 2021 2021 NW Natural: Current: Unrealized loss on derivatives (1) $ 15,918 $ 3,393 $ 10,402 Gas costs 48,218 29,486 35,641 Environmental costs (2) 6,975 5,688 6,694 Decoupling (3) 212 1,011 969 Pension balancing (4) 7,131 7,131 7,131 Income taxes 2,276 2,345 2,568 Other (5) 12,073 11,618 8,986 Total current $ 92,803 $ 60,672 $ 72,391 Non-current: Unrealized loss on derivatives (1) $ 9,475 $ 453 $ 412 Pension balancing (4) 35,150 40,342 38,302 Income taxes 11,161 13,903 12,609 Pension and other postretirement benefit liabilities 110,548 160,385 116,440 Environmental costs (2) 86,411 85,423 94,636 Gas costs 7,975 5,742 15,477 Decoupling (3) — 198 — Other (5) 41,070 24,224 36,663 Total non-current $ 301,790 $ 330,670 $ 314,539 Other (NW Holdings) 65 40 40 Total non-current - NW Holdings $ 301,855 $ 330,710 $ 314,579 Regulatory Liabilities June 30, December 31, In thousands 2022 2021 2021 NW Natural: Current: Gas costs $ 1,898 $ 1,519 $ 70 Unrealized gain on derivatives (1) 60,652 46,168 48,130 Decoupling (3) 14,242 5,821 4,475 Income taxes 7,318 8,217 8,192 Asset optimization revenue sharing 9,761 39,348 45,124 Other (5) 3,406 2,137 6,290 Total current $ 97,277 $ 103,210 $ 112,281 Non-current: Gas costs $ 353 $ 101 $ 250 Unrealized gain on derivatives (1) 9,121 7,912 10,730 Decoupling (3) 2,557 652 3,412 Income taxes (6) 176,358 182,977 181,404 Accrued asset removal costs (7) 455,794 439,685 445,952 Asset optimization revenue sharing — — 1,810 Other (5) 13,760 12,850 13,792 Total non-current - NW Natural $ 657,943 $ 644,177 $ 657,350 Other (NW Holdings) 982 869 982 Total non-current - NW Holdings $ 658,925 $ 645,046 $ 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 NGD 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 16 for a description of environmental costs. (3) This deferral represents the margin adjustment resulting from differences between actual and expected volumes. (4) Balance represents deferred net periodic benefit costs as approved by the OPUC. (5) Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge. (6) Balance represents excess deferred income tax benefits subject to regulatory flow-through. (7) Estimated costs of removal on certain regulated properties are collected through rates. We believe all costs incurred and deferred at June 30, 2022 are prudent. All regulatory assets and liabilities are reviewed annually for recoverability, or more often if circumstances warrant. If we should determine that all or a portion of these regulatory assets or liabilities no longer meet the criteria for continued application of regulatory accounting, then NW Holdings and NW Natural would be required to write-off the net unrecoverable balances in the period such determination is made. Supplemental Cash Flow Information Restricted cash is primarily comprised of funds from public purpose charges for programs that assist low-income customers with bill payments or energy efficiency. The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Holdings as of June 30, 2022 and 2021 and December 31, 2021: June 30, December 31, In thousands 2022 2021 2021 Cash and cash equivalents $ 17,209 $ 20,084 $ 18,559 Restricted cash included in other current assets 12,826 8,226 8,561 Cash, cash equivalents and restricted cash $ 30,035 $ 28,310 $ 27,120 The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Natural as of June 30, 2022 and 2021 and December 31, 2021: June 30, December 31, In thousands 2022 2021 2021 Cash and cash equivalents $ 10,267 $ 11,488 $ 12,271 Restricted cash included in other current assets 12,826 8,226 8,561 Cash, cash equivalents and restricted cash $ 23,093 $ 19,714 $ 20,832 Accounts Receivable and Allowance for Uncollectible Accounts Accounts receivable consist primarily of amounts due for natural gas sales and transportation services to NGD customers, plus amounts due for gas storage services. NW Holdings and NW Natural establish allowances for uncollectible accounts (allowance) for trade receivables, including accrued unbilled revenue, based on the aging of receivables, collection experience of past due account balances including payment plans, and historical trends of write-offs as a percent of revenues. A specific allowance is established and recorded for large individual customer receivables when amounts are identified as unlikely to be partially or fully recovered. Inactive accounts are written-off against the allowance after they are 120 days past due or when deemed uncollectible. Differences between the estimated allowance and actual write-offs will occur based on a number of factors, including changes in economic conditions, customer creditworthiness, and natural gas prices. The allowance for uncollectible accounts is adjusted quarterly, as necessary, based on information currently available. Allowance for Trade Receivables The payment term of our NGD receivables is generally 15 days. For these short-term receivables, it is not expected that forecasted economic conditions would significantly affect the loss estimates under stable economic conditions. For extreme situations like a financial crisis, natural disaster, and the economic slowdown caused by the COVID-19 pandemic, we enhanced our review and analysis. During 2020 and 2021, we considered the significant exposure to COVID-19 related job losses in Oregon and Washington state, and expanded our standard review procedures for our allowance for uncollectible accounts at NW Holdings and NW Natural, including analyzing the unemployment rate and comparing it to historic economic data during the 2007-2009 time period when the country experienced an economic recession. We also considered other qualitative information including recent customer interactions related to payment plans and credit issues, statistics from our website related to credit inquiries, and bill assistance programs including the arrearage management program. For the residential allowance calculation, we continue to consider the funds applied or granted to customers through a variety of assistance programs including the COVID-19 arrearage management programs in Oregon and Washington. During the third quarter of 2021, the collection process for residential accounts resumed. For residential and commercial accounts, we've resumed collection processes and our provision is based on historical write-off trends and current information on delinquent accounts. For industrial accounts, we continue to analyze those accounts on an account-by-account basis with specific reserves taken as necessary. We’ll continue to closely monitor and evaluate our accounts receivable and provision for uncollectible accounts. 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 As of December 31, 2021 Six Months Ended June 30, 2022 June 30, 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 $ (142) $ (468) $ 850 Commercial 178 52 (110) 120 Industrial 67 110 (27) 150 Accrued unbilled and other 313 18 (95) 236 Total $ 2,018 $ 38 $ (700) $ 1,356 Allowance for Net Investments in Sales-Type Leases NW Natural currently holds two net investments in sales-type leases, with substantially all of the net investment balance related to the North Mist natural gas storage agreement with Portland General Electric (PGE) which is billed under an OPUC-approved rate schedule. See Note 7 for more information on the North Mist lease. Due to the nature of this service, PGE may recover the costs of the lease through general rate cases. Therefore, we expect the risk of loss due to the credit of this lessee to be remote. As such, no allowance for uncollectibility was recorded for our sales-type lease receivables. NW Natural will continue monitoring the credit health of the lessees and the overall economic environment, including the economic factors closely tied to the financial health of our current and future lessees. COVID-19 Impact During 2020, our regulated utilities received approval in their respective jurisdictions to defer certain financial impacts associated with COVID-19 such as bad debt expense, financing costs to secure liquidity, lost revenues related to late fees and reconnection fees, and other COVID-19 related costs, net of offsetting direct expense reductions associated with COVID-19. As of June 30, 2022 and 2021, we had a regulatory asset of approximately $13.4 million and $5.8 million, respectively, for incurred costs associated with COVID-19 that we believe are recoverable. Cloud Computing Arrangements (CCA) Implementation costs associated with its CCA are capitalized consistent with costs capitalized for internal-use software. Capitalized CCA implementation costs are included in other assets in the consolidated balance sheets. The CCA implementation costs are amortized over the term of the related hosting agreement, including renewal periods that are reasonably certain to be exercised. Amortization expense of CCA implementation costs are recorded as operations and maintenance expenses in the consolidated statements of comprehensive income. The CCA implementation costs are included within operating activities in the consolidated statements of cash flows. New Accounting Standards NW Natural and NW Holdings consider the applicability and impact of all accounting standards updates (ASUs) issued by the Financial Accounting Standards Board (FASB). ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on consolidated financial position or results of operations. Recently Adopted Accounting Pronouncements

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings or loss per share are computed using NW Holdings' net income or loss and the weighted average number of common shares outstanding for each period presented. Diluted earnings per share are computed in the same manner, except using the weighted average number of common shares outstanding plus the effects of the assumed exercise of stock options and the payment of estimated stock awards from other stock-based compensation plans that are outstanding at the end of each period presented. Anti-dilutive stock awards are excluded from the calculation of diluted earnings or loss per common share. NW Holdings' diluted earnings or loss per share are calculated as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands, except per share data 2022 2021 2022 2021 Net income (loss) 1,715 (724) 57,954 58,793 Average common shares outstanding - basic 34,307 30,664 32,756 30,639 Additional shares for stock-based compensation plans (See Note 8) 45 — 49 32 Average common shares outstanding - diluted 34,352 30,664 32,805 30,671 Earnings (loss) per share of common stock: Basic $ 0.05 $ (0.02) $ 1.77 $ 1.92 Diluted $ 0.05 $ (0.02) $ 1.77 $ 1.92 Additional information: Anti-dilutive shares 1 48 1 7

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2022
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We primarily operate in one reportable business segment, which is NW Natural's local gas distribution business and is referred to as the NGD s egment. NW Natural and NW Holdings also have investments and b usiness activities not specifically related to the NGD segment, which are aggregated and reported as other and described below for each entity. Natural Gas Distribution NW Natural's local gas distribution segment is a regulated utility principally engaged in the purchase, sale, and delivery of natural gas and related services to customers in Oregon and southwest Washington. In addition to NW Natural's local gas distribution business, the NGD segment also includes the portion of the Mist underground storage facility used to serve NGD customers, the North Mist gas storage expansion in Oregon, NWN Gas Reserves, which is a wholly-owned subsidiary of Energy Corp, and NW Natural RNG Holding Company, LLC, a holding company established to invest in the development and procurement of regulated renewable natural gas for NW Natural. NW Natural NW Natural's activities in Other include Interstate Storage Services and third-party asset management services for the Mist facility in Oregon, appliance retail center operations, and corporate operating and non-operating revenues and expenses that cannot be allocated to NGD operations. Earnings from Interstate Storage Services assets are primarily related to firm storage capacity revenues. Earnings from the Mist facility also include revenue, net of amounts shared with NGD customers, from management of NGD assets at Mist and upstream pipeline capacity when not needed to serve NGD customers. Under the Oregon sharing mechanism, NW Natural retains 80% of the pre-tax income from these services when the costs of the capacity were not included in NGD rates, or 10% of the pre-tax income when the costs have been included in these rates. The remaining 20% and 90%, respectively, are recorded to a deferred regulatory account for crediting back to NGD customers. NW Holdings NW Holdings' activities in Other include all remaining activities not associated with NW Natural, specifically: NWN Water, which consolidates the water and wastewater utility operations and is pursuing other investments in the water sector through itself and wholly-owned subsidiaries; NWN Water's equity investment in Avion Water Company, Inc. ; NWN Gas Storage, a wholly-owned subsidiary of NWN Energ y; other pipeline assets in NNG Financial; and NW Natural Renewables Holdings, LLC and its non-regulated renewable natural gas activities . Other a lso includes corporate revenues and expenses that cannot be allocated to other operations, including certain business development activities . Segment Information Summary Inter-segment transactions were immaterial for the periods presented. The following table presents summary financial information concerning the reportable segment and other. Three Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Operating revenues $ 184,634 $ 5,617 $ 190,251 $ 4,709 $ 194,960 Depreciation 27,062 266 27,328 782 28,110 Income (loss) from operations 10,575 3,550 14,125 (586) 13,539 Net income (loss) 157 2,576 2,733 (1,018) 1,715 Capital expenditures 91,122 750 91,872 7,310 99,182 2021 Operating revenues $ 139,614 $ 4,965 $ 144,579 $ 4,338 $ 148,917 Depreciation 27,273 257 27,530 614 28,144 Income (loss) from operations 11,331 2,808 14,139 (1,515) 12,624 Net income (loss) (1,381) 1,970 589 (1,313) (724) Capital expenditures 60,376 693 61,069 3,337 64,406 Six Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Operating revenues $ 526,032 $ 10,843 $ 536,875 $ 8,386 $ 545,261 Depreciation 54,435 530 54,965 1,574 56,539 Income (loss) from operations 96,238 6,438 102,676 (1,499) 101,177 Net income (loss) 55,547 4,602 60,149 (2,195) 57,954 Capital expenditures 155,402 787 156,189 11,507 167,696 Total assets at June 30, 2022 3,875,237 54,760 3,929,997 170,521 4,100,518 2021 Operating revenues $ 440,952 $ 15,977 $ 456,929 $ 7,934 $ 464,863 Depreciation 54,186 513 54,699 1,542 56,241 Income (loss) from operations 97,818 11,439 109,257 (1,927) 107,330 Net income (loss) 52,544 8,156 60,700 (1,907) 58,793 Capital expenditures 124,368 799 125,167 4,941 130,108 Total assets at June 30, 2021 3,587,966 51,466 3,639,432 144,068 3,783,500 Total assets at December 31, 2021 3,846,112 52,260 3,898,372 166,232 4,064,604 Natural Gas Distribution Margin NGD margin is the primary financial measure used by the Chief Operating Decision Maker (CODM) , consisting of NGD operating revenues, reduced by the associated cost of gas, environmental remediation expense, and revenue taxes. The cost of gas purchased for NGD customers is generally a pass-through cost in the amount of revenues billed to regulated NGD customers. Environmental remediation expense represents collections received from customers through environmental recovery mechanisms in Oregon and Washington as well as adjustments for the Oregon environmental earnings test when applicable. This is offset by environmental remediation expense presented in operating expenses. Revenue taxes are collected from NGD customers and remitted to taxing authorities. The collections from customers are offset by the expense recognition of the obligation to the taxing authority. By subtracting cost of gas, environmental remediation expense, and revenue taxes from NGD operating revenues, NGD margin provides a key metric used by the CODM in assessing the performance of the NGD segment. The following table presents additional segment information concerning NGD margin: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NGD margin calculation: NGD distribution revenues $ 179,727 $ 134,849 $ 516,214 $ 431,402 Other regulated services 4,907 4,765 9,818 9,550 Total NGD operating revenues 184,634 139,614 526,032 440,952 Less: NGD cost of gas 79,776 41,249 225,420 153,515 Environmental remediation 2,272 1,509 6,970 5,286 Revenue taxes 8,208 5,650 21,532 18,305 NGD margin $ 94,378 $ 91,206 $ 272,110 $ 263,846

Equity

Equity	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Stockholders' Equity Note Disclosure	COMMON STOCK In August 2021, NW Holdings initiated an at-the-market (ATM) equity program by entering into an equity distribution agreement under which NW Holdings may issue and sell from time to time shares of common stock, no par value, having an aggregate gross sales price of up to $200 million. NW Holdings is under no obligation to offer and sell common stock under the ATM equity program, which expires in August 2024. Any shares of common stock offered under the ATM equity program are registered on NW Holdings’ universal shelf registration statement filed with the SEC. During the three months ended June 30, 2022, NW Holdings issued and sold 482,200 shares of common stock pursuant to the ATM equity program resulting in cash proceeds of $25.1 million, net of fees and commissions paid to agents of $0.4 million. During the six months ended June 30, 2022, NW Holdings issued and sold 678,101 shares of common stock pursuant to the ATM equity program resulting in cash proceeds of $35.2 million, net of fees and commissions paid to agents of $0.7 million. As of June 30, 2022, NW Holdings had $146.2 million of equity available for issuance under the program. The ATM equity program was initiated to raise funds for general corporate purposes, including equity contributions to NW Holdings’ subsidiaries, NW Natural and NW Natural Water. Contributions to NW Natural and NW Natural Water will be used for general corporate purposes. On April 1, 2022, NW Holdings issued and sold 2,875,000 shares of its common stock pursuant to a registration statement on Form S-3 and related prospectus settlement. NW Holdings received net offering proceeds, after deducting the underwriter's discounts and commissions and expenses payable by NW Holdings, of approximately $138.6 million. The proceeds are to be used for general corporate purposes, including repayment of its short-term indebtedness and/or making equity contributions to NW Holdings' subsidiaries, NW Natural, NW Natural Water and NW Natural Renewables. Contributions to NW Natural, NW Natural Water and NW Natural Renewables are to be used for general corporate purposes. Of the contributions received by NW Natural, $130.0 million was used to repay its short-term indebtedness.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2022
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer	REVENUE The following tables present disaggregated revenue: Three Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Natural gas sales $ 190,041 $ — $ 190,041 $ — $ 190,041 Gas storage revenue, net — 3,039 3,039 — 3,039 Asset management revenue, net — 1,142 1,142 — 1,142 Appliance retail center revenue — 1,436 1,436 — 1,436 Other revenue 628 — 628 4,709 5,337 Revenue from contracts with customers 190,669 5,617 196,286 4,709 200,995 Alternative revenue (10,333) — (10,333) — (10,333) Leasing revenue 4,298 — 4,298 — 4,298 Total operating revenues $ 184,634 $ 5,617 $ 190,251 $ 4,709 $ 194,960 2021 Natural gas sales $ 123,739 $ — $ 123,739 $ — $ 123,739 Gas storage revenue, net — 2,805 2,805 — 2,805 Asset management revenue, net — 817 817 — 817 Appliance retail center revenue — 1,343 1,343 — 1,343 Other revenue 399 — 399 4,338 4,737 Revenue from contracts with customers 124,138 4,965 129,103 4,338 133,441 Alternative revenue 11,083 — 11,083 — 11,083 Leasing revenue 4,393 — 4,393 — 4,393 Total operating revenues $ 139,614 $ 4,965 $ 144,579 $ 4,338 $ 148,917 Six Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Natural gas sales $ 527,337 $ — $ 527,337 $ — $ 527,337 Gas storage revenue, net — 5,796 5,796 — 5,796 Asset management revenue, net — 1,894 1,894 — 1,894 Appliance retail center revenue — 3,153 3,153 — 3,153 Other revenue 1,258 — 1,258 8,386 9,644 Revenue from contracts with customers 528,595 10,843 539,438 8,386 547,824 Alternative revenue (11,160) — (11,160) — (11,160) Leasing revenue 8,597 — 8,597 — 8,597 Total operating revenues $ 526,032 $ 10,843 $ 536,875 $ 8,386 $ 545,261 2021 Natural gas sales $ 419,822 $ — $ 419,822 $ — $ 419,822 Gas storage revenue, net — 5,300 5,300 — 5,300 Asset management revenue, net — 7,745 7,745 — 7,745 Appliance retail center revenue — 2,932 2,932 — 2,932 Other revenue 814 — 814 7,934 8,748 Revenue from contracts with customers 420,636 15,977 436,613 7,934 444,547 Alternative revenue 11,536 — 11,536 — 11,536 Leasing revenue 8,780 — 8,780 — 8,780 Total operating revenues $ 440,952 $ 15,977 $ 456,929 $ 7,934 $ 464,863 NW Natural's revenue represents substantially all of NW Holdings' revenue and is recognized for both registrants when the obligation to customers is satisfied and in the amount expected to be received in exchange for transferring goods or providing services. Revenue from contracts with customers contains one performance obligation that is generally satisfied over time, using the output method based on time elapsed, due to the continuous nature of the service provided. The transaction price is determined by a set price agreed upon in the contract or dependent on regulatory tariffs. Customer accounts are settled on a monthly basis or paid at time of sale and based on historical experience. It is probable that we will collect substantially all of the consideration to which we are entitled. We evaluated the probability of collection in accordance with the current expected credit losses standard. NW Holdings and NW Natural do not have any material contract assets, as net accounts receivable and accrued unbilled revenue balances are unconditional and only involve the passage of time until such balances are billed and collected. NW Holdings and NW Natural do not have any material contract liabilities. Revenue taxes are included in operating revenues with an equal and offsetting expense recognized in operating expenses in the consolidated statements of comprehensive income. Revenue-based taxes are primarily franchise taxes, which are collected from NGD customers and remitted to taxing authorities. Natural Gas Distribution Natural Gas Sales NW Natural's primary source of revenue is providing natural gas to customers in the NGD service territory, which includes residential, commercial, industrial and transportation customers. NGD revenue is generally recognized over time upon delivery of the gas commodity or service to the customer, and the amount of consideration received and recognized as revenue is dependent on the Oregon and Washington tariffs. Customer accounts are to be paid in full each month, and there is no right of return or warranty for services provided. Revenues include firm and interruptible sales and transportation services, franchise taxes recovered from the customer, late payment fees, service fees, and accruals for gas delivered but not yet billed (accrued unbilled revenue). The accrued unbilled revenue balance is based on estimates of deliveries during the period from the last meter reading and management judgment is required for a number of factors used in this calculation, including customer use and weather factors. We applied the significant financing practical expedient and have not adjusted the consideration NW Natural expects to receive from NGD customers for the effects of a significant financing component as all payment arrangements are settled annually. Due to the election of the right to invoice practical expedient, we do not disclose the value of unsatisfied performance obligations. Alternative Revenue Weather normalization (WARM) and decoupling mechanisms are considered to be alternative revenue programs. Alternative revenue programs are considered to be contracts between NW Natural and its regulator and are excluded from revenue from contracts with customers. Leasing Revenue Leasing revenue primarily consists of revenues from NW Natural's North Mist Storage contract with Portland General Electric (PGE) in support of PGE's gas-fired electric power generation facilities under an initial 30-year contract with options to extend, totaling up to an additional 50 years upon mutual agreement of the parties. The facility is accounted for as a sales-type lease with regulatory accounting deferral treatment. The investment is included in rate base under an established cost-of-service tariff schedule, with revenues recognized according to the tariff schedule and as such, profit upon commencement was deferred and will be amortized over the lease term. Leasing revenue also contains rental revenue from small leases of property owned by NW Natural to third parties. The majority of these transactions are accounted for as operating leases and the revenue is recognized over the term of the lease agreement. Lease revenue is excluded from revenue from contracts with customers. See Note 7 for additional information. NW Natural Other Gas Storage Revenue NW Natural's other revenue includes gas storage activity, which includes Interstate Storage Services used to store natural gas for customers. Gas storage revenue is generally recognized over time as the gas storage service is provided to the customer and the amount of consideration received and recognized as revenue is dependent on set rates defined per the storage agreements. Noncash consideration in the form of dekatherms of natural gas is received as consideration for providing gas injection services to gas storage customers. This noncash consideration is measured at fair value using the average spot rate. Customer accounts are generally paid in full each month, and there is no right of return or warranty for services provided. Revenues include firm and interruptible storage services, net of the profit sharing amount refunded to NGD customers. Asset Management Revenue Revenues include the optimization of third-party storage assets and pipeline capacity and are provided net of the profit sharing amount refunded to NGD customers. Certain asset management revenues received are recognized over time using a straight-line approach over the term of each contract, and the amount of consideration received and recognized as revenue is dependent on a variable pricing model. Variable revenues earned above guaranteed amounts are estimated and recognized at the end of each period using the most likely amount approach. Additionally, other asset management revenues may be based on a fixed rate. Generally, asset management accounts are settled on a monthly basis. As of June 30, 2022, u nrecognized revenue for the fixed component of the transaction price related to gas storage and asset management revenue was approximat ely $89.6 million. Of this amount, approximately $10.5 million will be recognized during the remainder of 2022, $18.6 million in 2023, $15.6 million in 2024, $13.5 million in 2025, $9.4 million in 2026 and $22.0 million thereafter. The amounts presented here are calculated using current contracted rates. Appliance Retail Center Revenue NW Natural owns and operates an appliance store that is open to the public, where customers can purchase natural gas home appliances. Revenue from the sale of appliances is recognized at the point in time in which the appliance is transferred to the third party responsible for delivery and installation services and when the customer has legal title to the appliance. It is required that the sale be paid for in full prior to transfer of legal title. The amount of consideration received and recognized as revenue varies with changes in marketing incentives and discounts offered to customers. NW Holdings Other NW Holdings' primary source of other revenue is providing water and wastewater services to customers. Water and wastewater service revenue is generally recognized over time upon delivery of the water commodity or service to the customer, and the amount of consideration received and recognized as revenue is dependent on the tariffs established in the states we operate. Customer accounts are to be paid in full each month or bi-monthly, and there is no right of return or warranty for services provided. We applied the significant financing practical expedient and have not adjusted the consideration we expect to receive from water distribution and wastewater collection customers for the effects of a significant financing component as all payment arrangements are settled annually. Due to the election of the right to invoice practical expedient, we do not disclose the value of unsatisfied performance obligations.

Leases

Leases	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Lessee, Operating Leases	LEASES Lease Revenue Leasing revenue primarily consists of NW Natural's North Mist natural gas storage agreement with Portland General Electric (PGE), which is billed under an OPUC-approved rate schedule and includes an initial 30-year term beginning May 2019 with options to extend, totaling up to an additional 50 years upon mutual agreement of the parties. Under U.S. GAAP, this agreement is classified as a sales-type lease and qualifies for regulatory accounting deferral treatment. The investment in the storage facility is included in rate base under a separately established cost-of-service tariff, with revenues recognized according to the tariff schedule. As such, the selling profit that was calculated upon commencement as part of the sale-type lease recognition was deferred and will be amortized over the lease term. Billing rates under the cost-of-service tariff will be updated annually to reflect current information including depreciable asset levels, forecasted operating expenses, and the results of regulatory proceedings, as applicable, and revenue received under this agreement is recognized as operating revenue on the consolidated statements of comprehensive income. There are no variable payments or residual value guarantees. The lease does not contain an option to purchase the underlying assets. NW Natural also maintains a sales-type lease for specialized compressor facilities to provide high pressure compressed natural gas (CNG) services. Lease payments are outlined in an OPUC-approved rate schedule over a 10-year term. There are no variable payments or residual value guarantees. The selling profit computed upon lease commencement was not significant. Our lessor portfolio also contains small leases of property owned by NW Natural and NW Holdings to third parties. These transactions are accounted for as operating leases and the revenue is recognized over the term of the lease agreement. The components of lease revenue at NW Natural were as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 Lease revenue Operating leases $ 19 $ 25 $ 37 $ 43 Sales-type leases 4,279 4,368 8,560 8,737 Total lease revenue $ 4,298 $ 4,393 $ 8,597 $ 8,780 Additionally, lease revenue of $0.1 million was recognized for the three months ended June 30, 2022 and 2021 and lease revenue of $0.3 million was recognized for the six months ended June 30, 2022 and 2021 related to operating leases associated with non-utility property rentals. Lease revenue related to these leases was presented in other income (expense), net on the consolidated statements of comprehensive income as it is non-operating income. Total future minimum lease payments to be received under non-cancelable leases at June 30, 2022 are as follows: In thousands Operating Sales-Type Total NW Natural: Remainder of 2022 $ 289 $ 8,460 $ 8,749 2023 76 16,557 16,633 2024 76 15,867 15,943 2025 67 15,306 15,373 2026 36 14,901 14,937 Thereafter 22 236,820 236,842 Total minimum lease payments $ 566 $ 307,911 $ 308,477 Less: imputed interest 171,122 Total leases receivable $ 136,789 Other (NW Holdings): Remainder of 2022 $ 25 $ — $ 25 2023 51 — 51 2024 52 — 52 2025 53 — 53 2026 56 — 56 Thereafter 914 — 914 Total minimum lease payments $ 1,151 $ — $ 1,151 NW Holdings: Remainder of 2022 $ 314 $ 8,460 $ 8,774 2023 127 16,557 16,684 2024 128 15,867 15,995 2025 120 15,306 15,426 2026 92 14,901 14,993 Thereafter 936 236,820 237,756 Total minimum lease payments $ 1,717 $ 307,911 $ 309,628 Less: imputed interest 171,122 Total leases receivable $ 136,789 The total leases receivable above is reported under the NGD segment and the short- and long-term portions are included within other current assets and assets under sales-type leases on the consolidated balance sheets, respectively. The total amount of unguaranteed residual assets was $4.9 million, $4.5 million and $4.7 million at June 30, 2022 and 2021 and December 31, 2021, respectively, and is included in assets under sales-type leases on the consolidated balance sheets. Additionally, under regulatory accounting, the revenues and expenses associated with these agreements are presented on the consolidated statements of comprehensive income such that their presentation aligns with similar regulated activities at NW Natural. Lease Expense Operating Leases We have operating leases for land, buildings and equipment. Our primary lease is for NW Natural's headquarters and operations center. Our leases have remaining lease terms of three months to 18 years. Many of our lease agreements include options to extend the lease, which we do not include in our minimum lease terms unless they are reasonably certain to be exercised. Short-term leases with a term of 12 months or less are not recorded on the balance sheet. As most of our leases do not provide an implicit rate and are entered into by NW Natural, we use an estimated discount rate representing the rate we would have incurred to finance the funds necessary to purchase the leased asset and is based on information available at the lease commencement date in determining the present value of lease payments. The components of lease expense, a portion of which is capitalized, were as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NW Natural: Operating lease expense $ 1,741 $ 1,710 $ 3,468 $ 3,388 Short-term lease expense $ 416 $ 349 $ 579 $ 569 Other (NW Holdings): Operating lease expense $ 8 $ 18 $ 15 $ 36 NW Holdings: Operating lease expense $ 1,749 $ 1,728 $ 3,483 $ 3,424 Short-term lease expense $ 416 $ 349 $ 579 $ 569 Supplemental balance sheet information related to operating leases as of June 30, 2022 and 2021 and December 31, 2021 is as follows: In thousands June 30, December 31, 2022 2021 2021 NW Natural: Operating lease right of use asset $ 73,706 $ 76,211 $ 74,987 Operating lease liabilities - current liabilities $ 1,298 $ 1,193 $ 1,273 Operating lease liabilities - non-current liabilities 78,789 80,043 79,431 Total operating lease liabilities $ 80,087 $ 81,236 $ 80,704 Other (NW Holdings): Operating lease right of use asset $ 48 $ 83 $ 62 Operating lease liabilities - non-current liabilities 37 45 37 Operating lease liabilities - current liabilities $ 17 $ 35 $ 23 Total operating lease liabilities $ 54 $ 80 $ 60 NW Holdings: Operating lease right of use asset $ 73,754 $ 76,294 $ 75,049 Operating lease liabilities - current liabilities $ 1,315 $ 1,228 $ 1,296 Operating lease liabilities - non-current liabilities 78,826 80,088 79,468 Total operating lease liabilities $ 80,141 $ 81,316 $ 80,764 The weighted-average remaining lease terms and weighted-average discount rates for the operating leases at NW Natural were as follows: In thousands June 30, December 31, 2022 2021 2021 Weighted-average remaining lease term (years) 17.7 18.7 18.2 Weighted-average discount rate 7.2 % 7.2 % 7.2 % Headquarters and Operations Center Lease NW Natural commenced a 20-year operating lease agreement in March 2020 for a new headquarters and operations center in Portland, Oregon. There is an option to extend the term of the lease for two additional periods of seven years. There is a material timing difference between the minimum lease payments and expense recognition as calculated under operating lease accounting rules. OPUC issued an order allowing us to align our expense recognition with cash payments for ratemaking purposes. We recorded the difference between the minimum lease payments and the aggregate of the imputed interest on the finance lease obligation and amortization of the right-of-use asset as a deferred regulatory asset on our balance sheet. The balance of the regulatory asset was $6.3 million, $5.0 million and $5.7 million as of June 30, 2022 and 2021 and December 31, 2021, respectively. Maturities of operating lease liabilities at June 30, 2022 were as follows: In thousands NW Natural Other NW Holdings Remainder of 2022 $ 3,502 $ 12 $ 3,514 2023 7,013 6 7,019 2024 7,150 6 7,156 2025 7,185 6 7,191 2026 7,353 6 7,359 Thereafter 116,431 23 116,454 Total lease payments 148,634 59 148,693 Less: imputed interest 68,547 5 68,552 Total lease obligations 80,087 54 80,141 Less: current obligations 1,298 17 1,315 Long-term lease obligations $ 78,789 $ 37 $ 78,826 As of June 30, 2022, finance lease liabilities with maturities of less than one year were $0.1 million at NW Natural. Supplemental cash flow information related to leases was as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NW Natural: Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,733 $ 1,717 $ 3,466 $ 3,386 Finance cash flows from finance leases $ 307 $ 134 $ 382 $ 678 Right of use assets obtained in exchange for lease obligations Operating leases $ (14) $ — $ — $ 154 Finance leases $ 120 $ 20 $ 220 $ 94 Other (NW Holdings): Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6 $ 17 $ 12 $ 33 NW Holdings: Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,739 $ 1,734 $ 3,478 $ 3,419 Finance cash flows from finance leases $ 307 $ 134 $ 382 $ 678 Right of use assets obtained in exchange for lease obligations Operating leases $ (14) $ — $ — $ 154 Finance leases $ 120 $ 20 $ 220 $ 94 Finance Leases

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION Stock-based compensation plans are designed to promote stock ownership in NW Holdings by employees and officers. These compensation plans include a Long Term Incentive Plan (LTIP) and an Employee Stock Purchase Plan (ESPP). For additional information on stock-based compensation plans, see Note 8 in the 2021 Form 10-K and the updates provided below. Long Term Incentive Plan Performance Shares LTIP performance shares incorporate a combination of market, performance, and service-based factors. During the six months ended June 30, 2022, the final performance factor under the 2020 LTIP was approved and 31,830 performance-based shares were granted under the 2020 LTIP for accounting purposes. As such, NW Natural and other subsidiaries began recognizing compensation expense. In February 2021 and 2022, LTIP shares were awarded to participants; however, the agreements allow for one of the performance factors to remain variable until the first quarter of the third year of the award period. As the performance factor will not be approved until the first quarters of 2023 and 2024, respectively, there is not a mutual understanding of the awards' key terms and conditions between NW Holdings and the participants as of June 30, 2022, and therefore, no expense was recognized for the 2021 and 2022 awards. NW Holdings will calculate the grant date fair value and NW Natural will recognize expense over the remaining service period for each award once the final performance factor has been approved. For the 2021 and 2022 LTIP awards, share payouts range from a threshold of 0% to a maximum of 200% based on achievement of pre-established goals. The performance criteria for the 2021 and 2022 performance shares consists of a three-year Return on Invested Capital (ROIC) threshold that must be satisfied and a cumulative EPS factor, which can be modified by a total shareholder return factor (TSR modifier) relative to the performance of peer group companies over the performance period of three years for each respective award. If the targets were achieved for the 2021 and 2022 awards, NW Holdings would grant for accounting purposes 56,335 and 56,885 shares in the first quarters of 2023 and 2024, respectively. As of June 30, 2022, there wa s $0.2 million of unrecognized compensation cost associated with the 2020 LTIP grants, which is expected to be recognized through 2022. Restricted Stock Units During the six months ended June 30, 2022, 46,812 RSUs were granted under the LTIP with a weighted-average grant date fair value of $46.60 per share. Generally, the RSUs awarded are forfeitable and include a performance-based threshold as well as a vesting period of four years from the grant date. The majority of our RSU grants obligate NW Holdings, upon vesting, to issue the RSU holder one share of common stock. The grant may also include a cash payment equal to the total amount of dividends paid per share between the grant date and vesting date of that portion of the RSU depending on the structure of the award agreement. The fair value of an RSU is equal to the closing market price of NW Holdings' common stock on the grant date. As of June 30, 2022, there was $4.2 million of unrecognized compensation cost from grants of RSUs, which is expected to be recognized over a period extending through 2026.

Debt

Debt	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Debt	DEBT Short-Term Debt At June 30, 2022, NW Holdings and NW Natural had short-term debt outstanding of $222.7 million and $78.7 million, respectively. NW Holdings' short-term debt consisted of $144.0 million of balances outstanding under the credit agreement at NW Holdings and $78.7 million of commercial paper outstanding at NW Natural. The weighted average interest rate on the credit agreement at June 30, 2022 was 2.7% at NW Holdings. The weighted average interest rate of commercial paper at June 30, 2022 was 2.0% at NW Natural. At June 30, 2022, NW Natural's commercial paper had a maximum remaining maturity of 22 days and an average remaining maturity of 13 days. In June 2021, NW Natural entered into a $100.0 million 364-Day Term Loan Credit Agreement (Term Loan) and borrowed the full amount. All principal and interest under the Term Loan was repaid in December 2021. Long-Term Debt At June 30, 2022, NW Holdings and NW Natural had long-term debt outstanding of $1,045.9 million and $986.8 million, respectively, which included $8.0 million and $7.9 million of unamortized debt issuance costs at NW Holdings and NW Natural, respectively. NW Natural's long-term debt consists of first mortgage bonds (FMBs) with maturity dates ranging from 2023 through 2051, interest rates ranging from 2.8% to 7.9%, and a weighted average interest rate of 4.4%. No long-term debt is scheduled to mature over the next twelve months following June 30, 2022 at NW Natural. In June 2019, NW Natural Water, a wholly-owned subsidiary of NW Holdings, entered into a two In June 2021, NW Natural Water entered into a five guaranteed by NW Holdings and requires NW Holdings to maintain a consolidated indebtedness to total capitalization ratio of 70% or less. Failure to comply with this covenant would entitle the lenders to terminate their lending commitments and accelerate the maturity of all amounts outstanding. NW Holdings was in compliance with this covenant at June 30, 2022, with a consolidated indebtedness to total capitalization ratio of 52.7%. Fair Value of Long-Term Debt NW Holdings' and NW Natural's outstanding debt does not trade in active markets. The fair value of debt is estimated using the value of outstanding debt at natural gas distribution companies with similar credit ratings, terms, and remaining maturities to NW Holdings' and NW Natural's debt that actively trade in public markets. Substantially all outstanding debt at NW Holdings is comprised of NW Natural debt. These valuations are based on Level 2 inputs as defined in the fair value hierarchy. See Note 2 in the 2021 Form 10-K for a description of the fair value hierarchy. 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: June 30, December 31, In thousands 2022 2021 2021 NW Natural: Gross long-term debt $ 994,700 $ 924,700 $ 994,700 Unamortized debt issuance costs (7,938) (7,291) (8,205) Carrying amount $ 986,762 $ 917,409 $ 986,495 Estimated fair value (1) $ 891,064 $ 1,043,696 $ 1,110,741 NW Holdings: Gross long-term debt $ 1,053,912 $ 983,221 $ 1,053,241 Unamortized debt issuance costs (8,031) (7,446) (8,309) Carrying amount $ 1,045,881 $ 975,775 $ 1,044,932 Estimated fair value (1) $ 950,597 $ 1,104,230 $ 1,174,500 (1) Estimated fair value does not include unamortized debt issuance costs.

Pension and Other Postretiremen

Pension and Other Postretirement Benefit Costs	6 Months Ended
	Jun. 30, 2022
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension and Other Postretirement Benefit Costs	PENSION AND OTHER POSTRETIREMENT BENEFIT COSTS NW Natural maintains a qualified non-contributory defined benefit pension plan (Pension Plan), non-qualified supplemental pension plans for eligible executive officers and other key employees, and other postretirement employee benefit plans. NW Natural also has a qualified defined contribution plan (Retirement K Savings Plan) for all eligible employees. The Pension Plan and Retirement K Savings Plan have plan assets, which are held in qualified trusts to fund retirement benefits. The service cost component of net periodic benefit cost for NW Natural pension and other postretirement benefit plans is recognized in operations and maintenance expense in the consolidated statements of comprehensive income. The other non-service cost components are recognized in other income (expense), net in the consolidated statements of comprehensive income. The following table provides the components of net periodic benefit cost for the pension and other postretirement benefit plans: Three Months Ended June 30, Six Months Ended June 30, Pension Benefits Other Postretirement Pension Benefits Other In thousands 2022 2021 2022 2021 2022 2021 2022 2021 Service cost $ 1,529 $ 1,714 $ 47 $ 56 $ 3,059 $ 3,428 $ 94 $ 111 Interest cost 3,659 3,342 179 165 7,318 6,685 359 330 Expected return on plan assets (6,427) (6,099) — — (12,854) (12,198) — — Amortization of prior service credit — — (84) (117) — — (167) (234) Amortization of net actuarial loss 3,199 5,500 99 131 6,397 11,001 198 262 Net periodic benefit cost 1,960 4,457 241 235 3,920 8,916 484 469 Amount allocated to construction (616) (743) (17) (22) (1,280) (1,469) (35) (43) Net periodic benefit cost charged to expense 1,344 3,714 224 213 2,640 7,447 449 426 Amortization of regulatory balancing account 1,281 1,281 — — 4,082 4,082 — — Net amount charged to expense $ 2,625 $ 4,995 $ 224 $ 213 $ 6,722 $ 11,529 $ 449 $ 426 Net periodic benefit costs are reduced by amounts capitalized to NGD plant. In addition, net periodic benefit costs were recorded to a regulatory balancing account as approved by the OPUC and amortized accordingly. The following table presents amounts recognized in accumulated other comprehensive loss (AOCL) and the changes in AOCL related to non-qualified employee benefit plans: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 Beginning balance $ (11,207) $ (12,681) $ (11,404) $ (12,902) Amounts reclassified from AOCL: Amortization of actuarial losses 268 301 536 602 Total reclassifications before tax 268 301 536 602 Tax benefit (71) (80) (142) (160) Total reclassifications for the period 197 221 394 442 Ending balance $ (11,010) $ (12,460) $ (11,010) $ (12,460) Employer Contributions to Company-Sponsored Defined Benefit Pension Plans NW Natural made no cash contributions to its qualified defined benefit pension plans during the six months ended June 30, 2022 compared to $9.6 million for the same period in 2021. NW Natural does not expect to make any plan contributions during the remainder of 2022 as a result of adopting the American Rescue Plan Act. Defined Contribution Plan NW Natural's Retirement K Savings Plan is a qualified defined contribution plan under Internal Revenue Code Sections 401(a) and 401(k). NW Natural contributions totaled $5.2 million and $4.7 million for the six months ended June 30, 2022 and 2021, respectively. See Note 10 in the 2021 Form 10-K for more information concerning these retirement and other postretirement benefit plans.

Income Tax

Income Tax	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Tax	INCOME TAX An estimate of annual income tax expense is made each interim period using estimates for annual pre-tax income, regulatory flow-through adjustments, tax credits, and other items. The estimated annual effective tax rate is applied to year-to-date, pre-tax income to determine income tax expense for the interim period consistent with the annual estimate. Discrete events are recorded in the interim period in which they occur or become known. The effective income tax rate varied from the federal statutory rate due to the following: Three Months Ended June 30, NW Holdings NW Natural In thousands 2022 2021 2022 2021 Income tax at statutory rate (federal) $ 460 $ (210) $ 744 $ 184 State income tax 161 (48) 219 41 Increase (decrease): Differences required to be flowed-through by regulatory commissions (62) 21 (62) 21 Other, net (89) (40) (91) 42 Total provision for income taxes $ 470 $ (277) $ 810 $ 288 Effective income tax rate 21.5 % 27.7 % 22.9 % 32.8 % Six Months Ended June 30, NW Holdings NW Natural In thousands 2022 2021 2022 2021 Income tax at statutory rate (federal) $ 16,243 $ 16,598 $ 16,859 $ 17,123 State income tax 6,674 7,260 6,803 7,366 Increase (decrease): Differences required to be flowed-through by regulatory commissions (3,235) (3,584) (3,235) (3,584) Other, net (289) (30) (294) (65) Total provision for income taxes $ 19,393 $ 20,244 $ 20,133 $ 20,840 Effective income tax rate 25.1 % 25.6 % 25.1 % 25.6 % The NW Holdings and NW Natural effective income tax rates for the six months ended June 30, 2022 compared to the same period in 2021 changed primarily as a result of changes in pre-tax income. See Note 11 in the 2021 Form 10-K for more detail on income taxes and effective tax rates. The IRS Compliance Assurance Process (CAP) examination of the 2020 tax year was completed during the first quarter of 2022. There were no material changes to the return as filed. The 2021 and 2022 tax years are subject to examination under CAP.

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	PROPERTY, PLANT, AND EQUIPMENT The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation: June 30, December 31, In thousands 2022 2021 2021 NW Natural: NGD plant in service $ 3,782,197 $ 3,623,092 $ 3,721,939 NGD construction work in progress 195,118 99,646 135,398 Less: Accumulated depreciation 1,121,444 1,068,603 1,098,715 NGD plant, net 2,855,871 2,654,135 2,758,622 Other plant in service 69,623 66,315 69,332 Other construction work in progress 5,529 5,817 4,971 Less: Accumulated depreciation 21,167 20,140 20,646 Other plant, net 53,985 51,992 53,657 Total property, plant, and equipment, net $ 2,909,856 $ 2,706,127 $ 2,812,279 Other (NW Holdings): Other plant in service $ 59,718 $ 50,148 $ 57,184 Other construction work in progress 17,051 4,774 8,419 Less: Accumulated depreciation 7,944 5,120 6,512 Other plant, net $ 68,825 $ 49,802 $ 59,091 NW Holdings: Total property, plant, and equipment, net $ 2,978,681 $ 2,755,929 $ 2,871,370 NW Natural: Capital expenditures in accrued liabilities $ 44,052 $ 37,968 $ 37,537 NW Holdings: Capital expenditures in accrued liabilities $ 45,079 $ 38,395 $ 38,333 NW Natural Other plant balances include non-utility gas storage assets at the Mist facility and other long-lived assets not related to NGD. NW Holdings Other plant balances include long-lived assets associated with water and wastewater operations and non-regulated activities not held by NW Natural or its subsidiaries.

Investments

Investments	6 Months Ended
	Jun. 30, 2022
Investments [Abstract]
Investments [Text Block]	INVESTMENTS Investments include gas reserves, financial investments in life insurance policies, and equity method investments. The following table summarizes other investments: NW Holdings NW Natural June 30, December 31, June 30, December 31, In thousands 2022 2021 2021 2022 2021 2021 Investments in life insurance policies $ 48,735 $ 47,695 $ 48,178 $ 48,735 $ 47,695 $ 48,178 Investments in gas reserves, non-current 24,695 29,852 26,608 24,695 29,852 26,608 Investment in unconsolidated affiliates 22,597 30 14,492 8,056 — — Total other investments $ 96,027 $ 77,577 $ 89,278 $ 81,486 $ 77,547 $ 74,786 Investment in Life Insurance Policies Other investments include financial investments in life insurance policies, which are accounted for at cash surrender value, net of policy loans. See Note 13 in the 2021 Form 10-K. NW Natural Gas Reserves NW Natural has invested $188 million through the gas reserves program in the Jonah Field located in Wyoming as of June 30, 2022. Gas reserves are stated at cost, net of regulatory amortization, with the associated deferred tax benefits of $5.3 million, $8.8 million, and $6.9 million, which are recorded as liabilities in the June 30, 2022, June 30, 2021, and December 31, 2021 consolidated balance sheets, respectively. NW Natural's investment is included in NW Holdings' and NW Natural's consolidated balance sheets under other current assets and other investments (non-current portion) with the maximum loss exposure limited to the investment balance. The amount of gas reserves included in other current assets was $4.3 million, $8.4 million, and $5.4 million as of June 30, 2022, June 30, 2021, and December 31, 2021, respectively. See Note 13 in the 2021 Form 10-K. Investments in Unconsolidated Affiliates In December 2021, NW Natural Water purchased a 37.3% ownership stake in Avion Water Company, Inc. (Avion Water), an investor-owned water utility for $14.5 million. In July 2022, NW Natural Water increased its ownership stake in Avion Water to 40.3% for an additional $1.0 million. Avion Water operates in Bend, Oregon and the surrounding communities, serving approximately 15,000 customer connections and employing 35 people. The carrying value of the equity method investment is $10.4 million higher than the underlying equity in the net assets of the investee at June 30, 2022 due to equity method goodwill. Equity in earnings (loss) of Avion Water is included in other income (expense), net. In 2020, NW Natural began a partnership with BioCarbN to invest in up to four separate RNG development projects that will access biogas derived from water treatment at Tyson Foods’ processing plants, subject to approval by all parties. During the construction phase of the projects, NW Natural determined it is the primary beneficiary and fully consolidates each entity. In 2022, commissioning of the first project, Lexington Renewable Energy LLC (Lexington), was completed and NW Natural determined it was no longer the primary beneficiary and deconsolidated the variable interest entity and recorded the investment in Lexington as an equity method investment. NW Natural accounts for its interest in Lexington using the equity method of accounting because NW Natural does not control but has the ability to exercise significant influence over Lexington's operations after commissioning. There was no gain or loss recognized upon deconsolidation. NW Natural determined the fair value of the investment approximated the carrying value which was primarily comprised of cash and property, plant and equipment. As of June 30, 2022, NW Natural had an investment balance in Lexington of $8.1 million. Equity in earnings (loss) of Lexington is included in cost of gas.

Business Combinations Business

Business Combinations Business Combinations	6 Months Ended
	Jun. 30, 2022
Business Combinations [Abstract]
Business Combination Disclosure	BUSINESS COMBINATIONS 2022 Business Combinations During the six months ended June 30, 2022, NWN Water and its subsidiaries completed one acquisition qualifying as a business combination. The fair value of the preliminary consideration transferred was not material and is not significant to NW Holdings' results of operations. 2021 Business Combinations During 2021, NWN Water and its subsidiaries completed four acquisitions qualifying as business combinations. The aggregate fair value of the preliminary consideration transferred for these acquisitions were not material and are not significant to NW Holdings' results of operations. Goodwill NW Holdings allocates goodwill to reporting units based on the expected benefit from the business combination. We perform an annual impairment assessment of goodwill at the reporting unit level, or more frequently if events and circumstances indicate that goodwill might be impaired. An impairment loss is recognized if the carrying value of a reporting unit’s goodwill exceeds its fair value. As a result of all acquisitions completed, total goodwill was $70.7 million, $69.3 million, and $70.6 million as of June 30, 2022, June 30, 2021, and December 31, 2021, respectively. All of our goodwill is related to water and wastewater acquisitions and is included in the other category for segment reporting purposes. The annual impairment assessment of goodwill occurs in the fourth quarter of each year. There have been no impairments recognized to date.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	DERIVATIVE INSTRUMENTS NW Natural enters into financial derivative contracts to hedge a portion of the NGD segment's natural gas sales requirements. These contracts include swaps, options, and combinations of option contracts. These derivative financial instruments are primarily used to manage commodity price variability. A small portion of NW Natural's derivative hedging strategy involves foreign currency forward contracts. NW Natural enters into these financial derivatives, up to prescribed limits, primarily to hedge price variability related to term physical gas supply contracts as well as to hedge spot purchases of natural gas. The foreign currency forward contracts are used to hedge the fluctuation in foreign currency exchange rates for pipeline demand charges paid in Canadian dollars. In the normal course of business, NW Natural also enters into indexed-price physical forward natural gas commodity purchase contracts and options to meet the requirements of NGD customers. These contracts qualify for regulatory deferral accounting treatment. NW Natural also enters into exchange contracts related to the third-party asset management of its gas portfolio, some of which are derivatives that do not qualify for hedge accounting or only partial regulatory deferral, but are subject to NW Natural's regulatory sharing agreement. These derivatives are recognized in operating revenues, net of amounts shared with NGD customers. Notional Amounts The following table presents the absolute notional amounts related to open positions on NW Natural derivative instruments: June 30, December 31, In thousands 2022 2021 2021 Natural gas (in therms): Financial 718,965 680,335 618,815 Physical 516,590 419,148 431,628 Foreign exchange $ 7,659 $ 6,477 $ 6,268 Purchased Gas Adjustment (PGA) Under the PGA mechanism in Oregon, derivatives entered into by NW Natural for the procurement or hedging of natural gas for future gas years generally receive regulatory deferral accounting treatment. In general, commodity hedging for the current gas year is completed prior to the start of the gas year, and hedge prices are reflected in the weighted-average cost of gas in the PGA filing. Hedge contracts entered into prior to the PGA filing were included in the PGA for the 2021-22 gas year. Hedge contracts entered into after the start of the PGA period are subject to the PGA incentive sharing mechanism in Oregon. Under the PGA mechanism in Washington, NW Natural incorporates risk-responsive hedging strategies and receives regulatory deferral accounting treatment for its Washington gas supplies. NW Natural entered the 2021-22 gas year with its forecasted sales volumes hedged at approximately 79% in total. The total hedged for Oregon was approximately 82%, including 62% in financial hedges and 19% in physical gas supplies. The total hedged for Washington was approximately 57%, including 44% in financial hedges and 13% in physical gas supplies. Unrealized and Realized Gain/Loss The following table reflects the income statement presentation for the unrealized gains and losses from NW Natural's derivative instruments, which also represents all derivative instruments at NW Holdings: Three Months Ended June 30, 2022 2021 In thousands Natural gas commodity Foreign exchange Natural gas commodity Foreign exchange Benefit (expense) to cost of gas $ (29,332) $ (153) $ 16,323 $ (45) Operating revenues (expense) — — — — Amounts deferred to regulatory accounts on balance sheet 29,332 153 (16,323) 45 Total gain (loss) in pre-tax earnings $ — $ — $ — $ — Six Months Ended June 30, 2022 2021 In thousands Natural gas commodity Foreign exchange Natural gas commodity Foreign exchange Benefit (expense) to cost of gas $ 44,453 $ (73) $ 36,805 $ 32 Operating revenues (expense) — — (27) — Amounts deferred to regulatory accounts on balance sheet (44,453) 73 (36,782) (32) Total gain (loss) in pre-tax earnings $ — $ — $ (4) $ — Unrealized Gain/Loss Outstanding derivative instruments related to regulated NGD operations are deferred in accordance with regulatory accounting standards. The cost of foreign currency forward and natural gas derivative contracts are recognized immediately in the cost of gas; however, costs above or below the amount embedded in the current year PGA are subject to a regulatory deferral tariff and therefore, are recorded as a regulatory asset or liability. Realized Gain/Loss NW Natural realized net gains of $21.2 million and $57.2 million for the three and six months ended June 30, 2022, respectively, from the settlement of natural gas financial derivative contracts, whereas, net gains of $4.2 million and $9.3 million were realized for the three and six months ended June 30, 2021, respectively. Realized gains and losses offset the higher or lower cost of gas purchased, resulting in no incremental amounts to collect or refund to customers. Credit Risk Management of Financial Derivatives Instruments No collateral was posted with or by NW Natural counterparties as of June 30, 2022 or 2021. NW Natural attempts to minimize the potential exposure to collateral calls by diversifying counterparties and using credit limits to manage liquidity risk. Counterparties generally allow a certain credit limit threshold before requiring NW Natural to post collateral against unrealized loss positions. Given NW Natural's credit ratings, counterparty credit limits and portfolio diversification, it was not subject to collateral calls in 2022 or 2021. The collateral call exposure is set forth under credit support agreements, which generally contain credit limits. NW Natural could also be subject to collateral call exposure where it has agreed to provide adequate assurance, which is not specific as to the amount of credit limit allowed, but could potentially require additional collateral in the event of a material adverse change. NW Natural's financial derivative instruments are subject to master netting arrangements; however, they are presented on a gross basis in the consolidated balance sheets. NW Natural and its counterparties have the ability to set-off obligations to each other under specified circumstances. Such circumstances may include a defaulting party, a credit change due to a merger affecting either party, or any other termination event. NW Natural's current commodity financial swap and option contracts outstanding reflect unrealized gains of $46.6 million and $54.3 million at June 30, 2022 and 2021. If netted by counterparty, NW Natural's physical and financial derivative position would result in an asset of $47.8 million and a liability of $3.4 million as of June 30, 2022, an asset of $51.8 million and a liability of $1.6 million as of June 30, 2021, and an asset of $51.8 million and a liability of $3.8 million as of December 31, 2021. NW Natural is exposed to derivative credit and liquidity risk primarily through securing fixed price natural gas commodity swaps with financial counterparties. NW Natural utilizes master netting arrangements through International Swaps and Derivatives Association contracts to minimize this risk along with collateral support agreements with counterparties based on their credit ratings. In certain cases, NW Natural may require the posting of collateral, guarantees, or letters of credit from counterparties to maintain its minimum credit requirement standards. See Note 15 in the 2021 Form 10-K for additional information.

Environmental Matters

Environmental Matters	6 Months Ended
	Jun. 30, 2022
Environmental Remediation Obligations [Abstract]
Environmental Matters	ENVIRONMENTAL MATTERS NW Natural owns, or previously owned, properties that may require environmental remediation or action. The range of loss for environmental liabilities is estimated based on current remediation technology, enacted laws and regulations, industry experience gained at similar sites, and an assessment of the probable level of involvement and financial condition of other potentially responsible parties (PRPs). When amounts are prudently expended related to site remediation of those sites described herein, NW Natural has recovery mechanisms in place to collect 96.7% of remediation costs allocable to Oregon customers and 3.3% of costs allocable to Washington customers. These sites are subject to the remediation process prescribed by the Environmental Protection Agency (EPA) and the Oregon Department of Environmental Quality (ODEQ). The process begins with a remedial investigation (RI) to determine the nature and extent of contamination and then a risk assessment (RA) to establish whether the contamination at the site poses unacceptable risks to humans and the environment. Next, a feasibility study (FS) or an engineering evaluation/cost analysis (EE/CA) evaluates various remedial alternatives. It is at this point in the process when NW Natural is able to estimate a range of remediation costs and record a reasonable potential remediation liability, or make an adjustment to the existing liability. From this study, the regulatory agency selects a remedy and issues a Record of Decision (ROD). After a ROD is issued, NW Natural would seek to negotiate a consent decree or consent judgment for designing and implementing the remedy. NW Natural would have the ability to further refine estimates of remediation liabilities at that time. Remediation may include treatment of contaminated media such as sediment, soil and groundwater, removal and disposal of media, institutional controls such as legal restrictions on future property use, or natural recovery. Following construction of the remedy, the EPA and ODEQ also have requirements for ongoing maintenance, monitoring and other post-remediation care that may continue for many years. Where appropriate and reasonably known, NW Natural will provide for these costs in the remediation liabilities described below. Due to the numerous uncertainties surrounding the course of environmental remediation and the preliminary nature of several site investigations, in some cases, NW Natural may not be able to reasonably estimate the high end of the range of possible loss. In those cases, the nature of the possible loss has been disclosed, as has the fact that the high end of the range cannot be reasonably estimated where a range of potential loss is available. Unless there is an estimate within the range of possible losses that is more likely than other cost estimates within that range, NW Natural records the liability at the low end of this range. It is likely changes in these estimates and ranges will occur throughout the remediation process for each of these sites due to the continued evaluation and clarification concerning responsibility, the complexity of environmental laws and regulations and the determination by regulators of remediation alternatives. In addition to remediation costs, NW Natural could also be subject to Natural Resource Damages (NRD) claims. NW Natural will assess the likelihood and probability of each claim and recognize a liability if deemed appropriate. Refer to "Other Portland Harbor" below. Environmental Sites The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other current liabilities and other noncurrent liabilities in NW Natural's balance sheet: Current Liabilities Non-Current Liabilities June 30, December 31, June 30, December 31, In thousands 2022 2021 2021 2022 2021 2021 Portland Harbor site: Gasco/Siltronic Sediments $ 6,144 $ 6,658 $ 7,582 $ 40,740 $ 41,652 $ 42,076 Other Portland Harbor 2,313 2,195 2,592 8,613 6,588 9,570 Gasco/Siltronic Upland site 11,050 12,442 15,711 34,352 38,401 36,215 Front Street site 585 1,219 1,100 868 975 811 Oregon Steel Mills — — — 179 179 179 Total $ 20,092 $ 22,514 $ 26,985 $ 84,752 $ 87,795 $ 88,851 Portland Harbor Site The Portland Harbor is an EPA listed Superfund site that is approximately 10 miles long on the Willamette River and is adjacent to NW Natural's Gasco uplands site. NW Natural is one of over one hundred PRPs, each jointly and severally liable, at the Superfund site. In January 2017, the EPA issued its Record of Decision, which selects the remedy for the clean-up of the Portland Harbor site (Portland Harbor ROD). The Portland Harbor ROD estimates the present value total cost at approximately $1.05 billion with an accuracy between -30% and +50% of actual costs. NW Natural's potential liability is a portion of the costs of the remedy for the entire Portland Harbor Superfund site. The cost of that remedy is expected to be allocated among more than one hundred PRPs. NW Natural is participating in a non-binding allocation process with other PRPs in an effort to resolve its potential liability. The Portland Harbor ROD does not provide any additional clarification around allocation of costs among PRPs; accordingly, NW Natural has not modified any of the recorded liabilities at this time as a result of the issuance of the Portland Harbor ROD. NW Natural manages its liability related to the Superfund site as two distinct remediation projects: the Gasco Sediments Site and Other Portland Harbor projects. GASCO SEDIMENTS. In 2009, NW Natural and Siltronic Corporation entered into a separate Administrative Order on Consent with the EPA to evaluate and design specific remedies for sediments adjacent to the Gasco uplands and Siltronic uplands sites. NW Natural submitted a draft EE/CA to the EPA in May 2012 to provide the estimated cost of potential remedial alternatives for this site. In March 2020, NW Natural and the EPA amended the Administrative Order on Consent to include additional remedial design activities downstream of the Gasco sediments site and in the navigation channel. Siltronic Corporation is not a party to the amended order. In the second quarter of 2021, NW Natural began preliminary design discussions with the EPA for the Gasco sediments site. These preliminary design discussions did not include a cost estimate for cleanup. No design alternatives are more likely than the EE/CA alternatives at this time, and NW Natural expects further design discussion and iteration with the EPA. The estimated costs for the various sediment remedy alternatives in the draft EE/CA, for the additional studies and design work needed before the cleanup can occur, and for regulatory oversight throughout the cleanup range from $46.9 million to $350 million. NW Natural has recorded a liability of $46.9 million for the Gasco sediment clean-up, which reflects the low end of the range. At this time, we believe sediments at the Gasco sediments site represent the largest portion of NW Natural's liability related to the Portland Harbor site discussed above. OTHER PORTLAND HARBOR. While we believe liabilities associated with the Gasco sediments site represent NW Natural's largest exposure, there are other potential exposures associated with the Portland Harbor ROD, including NRD costs and harborwide remedial design and cleanup costs (including downstream petroleum contamination), for which allocations among the PRPs have not yet been determined. NW Natural and other parties have signed a cooperative agreement with the Portland Harbor Natural Resource Trustee council to participate in a phased NRD assessment to estimate liabilities to support an early restoration-based settlement of NRD claims. One member of this Trustee council, the Yakama Nation, withdrew from the council in 2009, and in 2017, filed suit against NW Natural and 29 other parties seeking remedial costs and NRD assessment costs associated with the Portland Harbor site, set forth in the complaint. The complaint seeks recovery of alleged costs totaling $0.3 million in connection with the selection of a remedial action for the Portland Harbor site as well as declaratory judgment for unspecified future remedial action costs and for costs to assess the injury, loss or destruction of natural resources resulting from the release of hazardous substances at and from the Portland Harbor site. The Yakama Nation has filed two amended complaints addressing certain pleading defects and dismissing the State of Oregon. On the motion of NW Natural and certain other defendants, the federal court has stayed the case pending the outcome of the non-binding allocation proceeding discussed above. NW Natural has recorded a liability for NRD claims which is at the low end of the range of the potential liability; the high end of the range cannot be reasonably estimated at this time. The NRD liability is not included in the aforementioned range of costs provided in the Portland Harbor ROD. Gasco Uplands Site A predecessor of NW Natural, Portland Gas and Coke Company, owned a former gas manufacturing plant that was closed in 1958 (Gasco site) and is adjacent to the Portland Harbor site described above. The Gasco site has been under investigation by NW Natural for environmental contamination under the ODEQ Voluntary Cleanup Program (VCP). It is not included in the range of remedial costs for the Portland Harbor site noted above. The Gasco site is managed in two parts, the uplands portion and the groundwater source control action. NW Natural submitted a revised Remedial Investigation Report for the uplands to ODEQ in May 2007. In March 2015, ODEQ approved the Risk Assessment (RA) for this site, enabling commencement of work on the FS in 2016. NW Natural has recognized a liability for the remediation of the uplands portion of the site which is at the low end of the range of potential liability; the high end of the range cannot be reasonably estimated at this time. In October 2016, ODEQ and NW Natural agreed to amend their VCP agreement for the Gasco uplands to incorporate a portion of the Siltronic property formerly owned by Portland Gas & Coke between 1939 and 1960 into the Gasco RA and FS. Previously, NW Natural was conducting an investigation of manufactured gas plant constituents on the entire Siltronic uplands for ODEQ. Siltronic will be working with ODEQ directly on environmental impacts to the remainder of its property. In September 2013, NW Natural completed construction of a groundwater source control system, including a water treatment station, at the Gasco site. NW Natural has estimated the cost associated with the ongoing operation of the system and has recognized a liability which is at the low end of the range of potential cost. NW Natural cannot estimate the high end of the range at this time due to the uncertainty associated with the duration of running the water treatment station, which is highly dependent on the remedy determined for both the upland portion as well as the final remedy for the Gasco sediments site. Other Sites In addition to those sites above, NW Natural has environmental exposures at three other sites: Central Service Center, Front Street and Oregon Steel Mills. NW Natural may have exposure at other sites that have not been identified at this time. Due to the uncertainty of the design of remediation, regulation, timing of the remediation and in the case of the Oregon Steel Mills site, pending litigation, liabilities for each of these sites have been recognized at their respective low end of the range of potential liability; the high end of the range could not be reasonably estimated at this time. FRONT STREET SITE. The Front Street site was the former location of a gas manufacturing plant NW Natural operated (the former Portland Gas Manufacturing site, or PGM). At ODEQ’s request, NW Natural conducted a sediment and source control investigation and provided findings to ODEQ. In December 2015, an FS on the former Portland Gas Manufacturing site was completed. In July 2017, ODEQ issued the PGM ROD. The ROD specifies the selected remedy, which requires a combination of dredging, capping, treatment, and natural recovery. In addition, the selected remedy also requires institutional controls and long-term inspection and maintenance. Construction of the remedy began in July 2020 and was completed in October 2020. The first year of post-construction monitoring was completed in 2021 and demonstrated that the cap was intact and performing as designed. NW Natural has recognized an additional liability of $1.5 million costs associated with the discovery during construction of World War II-era munitions, design costs, regulatory and permitting issues, and post-construction work. OREGON STEEL MILLS SITE. Refer to " Legal Proceedings" below. Environmental Cost Deferral and Recovery NW Natural has authorizations in Oregon and Washington to defer costs related to remediation of properties that are owned or were previously owned by NW Natural. In Oregon, a Site Remediation and Recovery Mechanism (SRRM) is currently in place to recover prudently incurred costs allocable to Oregon customers, subject to an earnings test. On October 21, 2019, the WUTC authorized an Environmental Cost Recovery Mechanism (ECRM) for recovery of prudently incurred costs allocable to Washington customers beginning November 1, 2019 . See Note 17 in the 2021 Form 10-K for a description of SRRM and ECRM collection processes. The following table presents information regarding the total regulatory asset deferred: June 30, December 31, In thousands 2022 2021 2021 Deferred costs and interest (1) $ 48,814 $ 50,604 $ 45,122 Accrued site liabilities (2) 104,798 110,237 115,773 Insurance proceeds and interest (60,226) (69,730) (59,564) Total regulatory asset deferral (1) $ 93,386 $ 91,111 $ 101,331 Current regulatory assets (3) 6,975 5,688 6,694 Long-term regulatory assets (3) 86,411 85,423 94,636 (1) Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers. (2) Exclude s 3.3% of the Front Street site liability as the OPUC only allows recovery of 96.7% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers. Amounts excluded from regulatory assets were $47 thousand at June 30, 2022, $72 thousand at June 30, 2021, and $62 thousand at December 31, 2021. (3) Environmental costs relate to specific sites approved for regulatory deferral by the OPUC and WUTC. In Oregon, NW Natural earns a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. It also accrues a carrying charge on insurance proceeds for amounts owed to customers. In Washington, neither the cash paid for insurance proceeds received accrue a carrying charge. Current environmental costs represent remediation costs management expects to collect from customers in the next 12 months. Amounts included in this estimate are still subject to a prudence and earnings test review by the OPUC and do not include the $5.0 million tariff rider. The amounts allocable to Oregon are recoverable through NGD rates, subject to an earnings test. Environmental Earnings Test To the extent NW Natural earns at or below its authorized Return on Equity (ROE) as defined by the SRRM, remediation expenses and interest in excess of the $5.0 million tariff rider and $5.0 million insurance proceeds are recoverable through the SRRM. To the extent NW Natural earns more than its authorized ROE in a year, it is required to cover environmental expenses and interest on expenses greater than the $10.0 million with those earnings that exceed its authorized ROE. Legal Proceedings NW Holdings is not currently party to any direct claims or litigation, though in the future it may be subject to claims and litigation arising in the ordinary course of business. NW Natural is subject to claims and litigation arising in the ordinary course of business including the matters discussed above. Although the final outcome of any of these legal proceedings cannot be predicted with certainty, including the matter relating to the Oregon Steel Mills site described below, NW Natural and NW Holdings do not expect that the ultimate disposition of any of these matters will have a material effect on their financial condition, results of operations or cash flows. See also Part II, Item 1, “Legal Proceedings". Oregon Steel Mills Site See Note 17 in the 2021 Form 10-K. For additional information regarding other commitments and contingencies, see Note 16 in the 2021 Form 10-K.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events [Text Block]	SUBSEQUENT EVENTOn July 15, 2022, NW Natural entered into a Bond Purchase Agreement between NW Natural and the institutional investors named as purchasers therein (the Bond Purchase Agreement). The Bond Purchase Agreement provides for the issuance of $140.0 million aggregate principal amount of NW Natural's First Mortgage Bonds, 4.78% Series due 2052 (the Bonds). The Bonds are expected to be issued on or about September 30, 2022. The Bonds will bear interest at the rate of 4.78% per annum, payable semi-annually on March 30 and September 30 of each year, commencing March 30, 2023, and will mature on September 30, 2052.The Bonds will be subject to redemption prior to maturity at the option of NW Natural, in whole or in part, (i) at any time prior to March 30, 2052, at a redemption price equal to 100% of the principal amount thereof plus a “make-whole” premium and accrued and unpaid interest thereon to the date of redemption, and (ii) at any time on and after March 30, 2052, at 100% of the principal amount thereof plus accrued and unpaid interest thereon to the date of redemption.

Significant Accounting Polici_2

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Industry Regulation	Industry Regulation In applying regulatory accounting principles, NW Holdings and NW Natural capitalize or defer certain costs and revenues as regulatory assets and liabilities pursuant to orders of the Oregon Public Utilities Commission (OPUC), Washington Utilities and Transportation Commission (WUTC), Idaho Public Utilities Commission (IPUC) or Public Utility Commission of Texas (PUCT), as applicable, which provide for the recovery of revenues or expenses from, or refunds to, utility customers in future periods, including a return or a carrying charge in certain cases.
New Accounting Standards	New Accounting Standards NW Natural and NW Holdings consider the applicability and impact of all accounting standards updates (ASUs) issued by the Financial Accounting Standards Board (FASB). ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on consolidated financial position or results of operations. Recently Adopted Accounting Pronouncements

Significant Accounting Polici_3

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Schedule of Regulatory Assets	Amounts deferred as regulatory assets and liabilities for NW Holdings and NW Natural were as follows: Regulatory Assets June 30, December 31, In thousands 2022 2021 2021 NW Natural: Current: Unrealized loss on derivatives (1) $ 15,918 $ 3,393 $ 10,402 Gas costs 48,218 29,486 35,641 Environmental costs (2) 6,975 5,688 6,694 Decoupling (3) 212 1,011 969 Pension balancing (4) 7,131 7,131 7,131 Income taxes 2,276 2,345 2,568 Other (5) 12,073 11,618 8,986 Total current $ 92,803 $ 60,672 $ 72,391 Non-current: Unrealized loss on derivatives (1) $ 9,475 $ 453 $ 412 Pension balancing (4) 35,150 40,342 38,302 Income taxes 11,161 13,903 12,609 Pension and other postretirement benefit liabilities 110,548 160,385 116,440 Environmental costs (2) 86,411 85,423 94,636 Gas costs 7,975 5,742 15,477 Decoupling (3) — 198 — Other (5) 41,070 24,224 36,663 Total non-current $ 301,790 $ 330,670 $ 314,539 Other (NW Holdings) 65 40 40 Total non-current - NW Holdings $ 301,855 $ 330,710 $ 314,579
Schedule of Regulatory Liabilities	Regulatory Liabilities June 30, December 31, In thousands 2022 2021 2021 NW Natural: Current: Gas costs $ 1,898 $ 1,519 $ 70 Unrealized gain on derivatives (1) 60,652 46,168 48,130 Decoupling (3) 14,242 5,821 4,475 Income taxes 7,318 8,217 8,192 Asset optimization revenue sharing 9,761 39,348 45,124 Other (5) 3,406 2,137 6,290 Total current $ 97,277 $ 103,210 $ 112,281 Non-current: Gas costs $ 353 $ 101 $ 250 Unrealized gain on derivatives (1) 9,121 7,912 10,730 Decoupling (3) 2,557 652 3,412 Income taxes (6) 176,358 182,977 181,404 Accrued asset removal costs (7) 455,794 439,685 445,952 Asset optimization revenue sharing — — 1,810 Other (5) 13,760 12,850 13,792 Total non-current - NW Natural $ 657,943 $ 644,177 $ 657,350 Other (NW Holdings) 982 869 982 Total non-current - NW Holdings $ 658,925 $ 645,046 $ 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 NGD 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 16 for a description of environmental costs. (3) This deferral represents the margin adjustment resulting from differences between actual and expected volumes. (4) Balance represents deferred net periodic benefit costs as approved by the OPUC. (5) Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge. (6) Balance represents excess deferred income tax benefits subject to regulatory flow-through.
Schedule of Cash Flow, Supplemental Disclosures	The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Holdings as of June 30, 2022 and 2021 and December 31, 2021: June 30, December 31, In thousands 2022 2021 2021 Cash and cash equivalents $ 17,209 $ 20,084 $ 18,559 Restricted cash included in other current assets 12,826 8,226 8,561 Cash, cash equivalents and restricted cash $ 30,035 $ 28,310 $ 27,120 The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Natural as of June 30, 2022 and 2021 and December 31, 2021: June 30, December 31, In thousands 2022 2021 2021 Cash and cash equivalents $ 10,267 $ 11,488 $ 12,271 Restricted cash included in other current assets 12,826 8,226 8,561 Cash, cash equivalents and restricted cash $ 23,093 $ 19,714 $ 20,832
Accounts Receivable, Allowance for Credit Loss [Table Text Block]	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 As of December 31, 2021 Six Months Ended June 30, 2022 June 30, 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 $ (142) $ (468) $ 850 Commercial 178 52 (110) 120 Industrial 67 110 (27) 150 Accrued unbilled and other 313 18 (95) 236 Total $ 2,018 $ 38 $ (700) $ 1,356

Earnings Per Share_2

Earnings Per Share	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
EPS Calculation	NW Holdings' diluted earnings or loss per share are calculated as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands, except per share data 2022 2021 2022 2021 Net income (loss) 1,715 (724) 57,954 58,793 Average common shares outstanding - basic 34,307 30,664 32,756 30,639 Additional shares for stock-based compensation plans (See Note 8) 45 — 49 32 Average common shares outstanding - diluted 34,352 30,664 32,805 30,671 Earnings (loss) per share of common stock: Basic $ 0.05 $ (0.02) $ 1.77 $ 1.92 Diluted $ 0.05 $ (0.02) $ 1.77 $ 1.92 Additional information: Anti-dilutive shares 1 48 1 7

Segment Information_2

Segment Information	6 Months Ended
	Jun. 30, 2022
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table presents summary financial information concerning the reportable segment and other. Three Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Operating revenues $ 184,634 $ 5,617 $ 190,251 $ 4,709 $ 194,960 Depreciation 27,062 266 27,328 782 28,110 Income (loss) from operations 10,575 3,550 14,125 (586) 13,539 Net income (loss) 157 2,576 2,733 (1,018) 1,715 Capital expenditures 91,122 750 91,872 7,310 99,182 2021 Operating revenues $ 139,614 $ 4,965 $ 144,579 $ 4,338 $ 148,917 Depreciation 27,273 257 27,530 614 28,144 Income (loss) from operations 11,331 2,808 14,139 (1,515) 12,624 Net income (loss) (1,381) 1,970 589 (1,313) (724) Capital expenditures 60,376 693 61,069 3,337 64,406 Six Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Operating revenues $ 526,032 $ 10,843 $ 536,875 $ 8,386 $ 545,261 Depreciation 54,435 530 54,965 1,574 56,539 Income (loss) from operations 96,238 6,438 102,676 (1,499) 101,177 Net income (loss) 55,547 4,602 60,149 (2,195) 57,954 Capital expenditures 155,402 787 156,189 11,507 167,696 Total assets at June 30, 2022 3,875,237 54,760 3,929,997 170,521 4,100,518 2021 Operating revenues $ 440,952 $ 15,977 $ 456,929 $ 7,934 $ 464,863 Depreciation 54,186 513 54,699 1,542 56,241 Income (loss) from operations 97,818 11,439 109,257 (1,927) 107,330 Net income (loss) 52,544 8,156 60,700 (1,907) 58,793 Capital expenditures 124,368 799 125,167 4,941 130,108 Total assets at June 30, 2021 3,587,966 51,466 3,639,432 144,068 3,783,500 Total assets at December 31, 2021 3,846,112 52,260 3,898,372 166,232 4,064,604
NGD Margin	The following table presents additional segment information concerning NGD margin: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NGD margin calculation: NGD distribution revenues $ 179,727 $ 134,849 $ 516,214 $ 431,402 Other regulated services 4,907 4,765 9,818 9,550 Total NGD operating revenues 184,634 139,614 526,032 440,952 Less: NGD cost of gas 79,776 41,249 225,420 153,515 Environmental remediation 2,272 1,509 6,970 5,286 Revenue taxes 8,208 5,650 21,532 18,305 NGD margin $ 94,378 $ 91,206 $ 272,110 $ 263,846

Revenue_2

Revenue	3 Months Ended
	Jun. 30, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables present disaggregated revenue: Three Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Natural gas sales $ 190,041 $ — $ 190,041 $ — $ 190,041 Gas storage revenue, net — 3,039 3,039 — 3,039 Asset management revenue, net — 1,142 1,142 — 1,142 Appliance retail center revenue — 1,436 1,436 — 1,436 Other revenue 628 — 628 4,709 5,337 Revenue from contracts with customers 190,669 5,617 196,286 4,709 200,995 Alternative revenue (10,333) — (10,333) — (10,333) Leasing revenue 4,298 — 4,298 — 4,298 Total operating revenues $ 184,634 $ 5,617 $ 190,251 $ 4,709 $ 194,960 2021 Natural gas sales $ 123,739 $ — $ 123,739 $ — $ 123,739 Gas storage revenue, net — 2,805 2,805 — 2,805 Asset management revenue, net — 817 817 — 817 Appliance retail center revenue — 1,343 1,343 — 1,343 Other revenue 399 — 399 4,338 4,737 Revenue from contracts with customers 124,138 4,965 129,103 4,338 133,441 Alternative revenue 11,083 — 11,083 — 11,083 Leasing revenue 4,393 — 4,393 — 4,393 Total operating revenues $ 139,614 $ 4,965 $ 144,579 $ 4,338 $ 148,917 Six Months Ended June 30, In thousands NGD Other NW Natural Other NW Holdings 2022 Natural gas sales $ 527,337 $ — $ 527,337 $ — $ 527,337 Gas storage revenue, net — 5,796 5,796 — 5,796 Asset management revenue, net — 1,894 1,894 — 1,894 Appliance retail center revenue — 3,153 3,153 — 3,153 Other revenue 1,258 — 1,258 8,386 9,644 Revenue from contracts with customers 528,595 10,843 539,438 8,386 547,824 Alternative revenue (11,160) — (11,160) — (11,160) Leasing revenue 8,597 — 8,597 — 8,597 Total operating revenues $ 526,032 $ 10,843 $ 536,875 $ 8,386 $ 545,261 2021 Natural gas sales $ 419,822 $ — $ 419,822 $ — $ 419,822 Gas storage revenue, net — 5,300 5,300 — 5,300 Asset management revenue, net — 7,745 7,745 — 7,745 Appliance retail center revenue — 2,932 2,932 — 2,932 Other revenue 814 — 814 7,934 8,748 Revenue from contracts with customers 420,636 15,977 436,613 7,934 444,547 Alternative revenue 11,536 — 11,536 — 11,536 Leasing revenue 8,780 — 8,780 — 8,780 Total operating revenues $ 440,952 $ 15,977 $ 456,929 $ 7,934 $ 464,863

Leases_2

Leases	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Lease Revenue	The components of lease revenue at NW Natural were as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 Lease revenue Operating leases $ 19 $ 25 $ 37 $ 43 Sales-type leases 4,279 4,368 8,560 8,737 Total lease revenue $ 4,298 $ 4,393 $ 8,597 $ 8,780
Lessor, Operating Lease, Payments to be Received, Maturity	Total future minimum lease payments to be received under non-cancelable leases at June 30, 2022 are as follows: In thousands Operating Sales-Type Total NW Natural: Remainder of 2022 $ 289 $ 8,460 $ 8,749 2023 76 16,557 16,633 2024 76 15,867 15,943 2025 67 15,306 15,373 2026 36 14,901 14,937 Thereafter 22 236,820 236,842 Total minimum lease payments $ 566 $ 307,911 $ 308,477 Less: imputed interest 171,122 Total leases receivable $ 136,789 Other (NW Holdings): Remainder of 2022 $ 25 $ — $ 25 2023 51 — 51 2024 52 — 52 2025 53 — 53 2026 56 — 56 Thereafter 914 — 914 Total minimum lease payments $ 1,151 $ — $ 1,151 NW Holdings: Remainder of 2022 $ 314 $ 8,460 $ 8,774 2023 127 16,557 16,684 2024 128 15,867 15,995 2025 120 15,306 15,426 2026 92 14,901 14,993 Thereafter 936 236,820 237,756 Total minimum lease payments $ 1,717 $ 307,911 $ 309,628 Less: imputed interest 171,122 Total leases receivable $ 136,789
Lease Expense	The components of lease expense, a portion of which is capitalized, were as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NW Natural: Operating lease expense $ 1,741 $ 1,710 $ 3,468 $ 3,388 Short-term lease expense $ 416 $ 349 $ 579 $ 569 Other (NW Holdings): Operating lease expense $ 8 $ 18 $ 15 $ 36 NW Holdings: Operating lease expense $ 1,749 $ 1,728 $ 3,483 $ 3,424 Short-term lease expense $ 416 $ 349 $ 579 $ 569
Operating Lease, Lease Asset and Liabilities	Supplemental balance sheet information related to operating leases as of June 30, 2022 and 2021 and December 31, 2021 is as follows: In thousands June 30, December 31, 2022 2021 2021 NW Natural: Operating lease right of use asset $ 73,706 $ 76,211 $ 74,987 Operating lease liabilities - current liabilities $ 1,298 $ 1,193 $ 1,273 Operating lease liabilities - non-current liabilities 78,789 80,043 79,431 Total operating lease liabilities $ 80,087 $ 81,236 $ 80,704 Other (NW Holdings): Operating lease right of use asset $ 48 $ 83 $ 62 Operating lease liabilities - non-current liabilities 37 45 37 Operating lease liabilities - current liabilities $ 17 $ 35 $ 23 Total operating lease liabilities $ 54 $ 80 $ 60 NW Holdings: Operating lease right of use asset $ 73,754 $ 76,294 $ 75,049 Operating lease liabilities - current liabilities $ 1,315 $ 1,228 $ 1,296 Operating lease liabilities - non-current liabilities 78,826 80,088 79,468 Total operating lease liabilities $ 80,141 $ 81,316 $ 80,764
Operating Lease, Weighted Average Remaining Term and Discount Rates [Table Text Block]	The weighted-average remaining lease terms and weighted-average discount rates for the operating leases at NW Natural were as follows: In thousands June 30, December 31, 2022 2021 2021 Weighted-average remaining lease term (years) 17.7 18.7 18.2 Weighted-average discount rate 7.2 % 7.2 % 7.2 %
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities at June 30, 2022 were as follows: In thousands NW Natural Other NW Holdings Remainder of 2022 $ 3,502 $ 12 $ 3,514 2023 7,013 6 7,019 2024 7,150 6 7,156 2025 7,185 6 7,191 2026 7,353 6 7,359 Thereafter 116,431 23 116,454 Total lease payments 148,634 59 148,693 Less: imputed interest 68,547 5 68,552 Total lease obligations 80,087 54 80,141 Less: current obligations 1,298 17 1,315 Long-term lease obligations $ 78,789 $ 37 $ 78,826
Lessee, Leases, Supplemental Cash Flow Information	Supplemental cash flow information related to leases was as follows: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 NW Natural: Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,733 $ 1,717 $ 3,466 $ 3,386 Finance cash flows from finance leases $ 307 $ 134 $ 382 $ 678 Right of use assets obtained in exchange for lease obligations Operating leases $ (14) $ — $ — $ 154 Finance leases $ 120 $ 20 $ 220 $ 94 Other (NW Holdings): Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6 $ 17 $ 12 $ 33 NW Holdings: Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,739 $ 1,734 $ 3,478 $ 3,419 Finance cash flows from finance leases $ 307 $ 134 $ 382 $ 678 Right of use assets obtained in exchange for lease obligations Operating leases $ (14) $ — $ — $ 154 Finance leases $ 120 $ 20 $ 220 $ 94

Debt_2

Debt	6 Months Ended
	Jun. 30, 2022
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: June 30, December 31, In thousands 2022 2021 2021 NW Natural: Gross long-term debt $ 994,700 $ 924,700 $ 994,700 Unamortized debt issuance costs (7,938) (7,291) (8,205) Carrying amount $ 986,762 $ 917,409 $ 986,495 Estimated fair value (1) $ 891,064 $ 1,043,696 $ 1,110,741 NW Holdings: Gross long-term debt $ 1,053,912 $ 983,221 $ 1,053,241 Unamortized debt issuance costs (8,031) (7,446) (8,309) Carrying amount $ 1,045,881 $ 975,775 $ 1,044,932 Estimated fair value (1) $ 950,597 $ 1,104,230 $ 1,174,500 (1) Estimated fair value does not include unamortized debt issuance costs.

Pension and Other Postretirem_2

Pension and Other Postretirement Benefit Costs	6 Months Ended
	Jun. 30, 2022
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Schedule of Net Benefit Costs	The following table provides the components of net periodic benefit cost for the pension and other postretirement benefit plans: Three Months Ended June 30, Six Months Ended June 30, Pension Benefits Other Postretirement Pension Benefits Other In thousands 2022 2021 2022 2021 2022 2021 2022 2021 Service cost $ 1,529 $ 1,714 $ 47 $ 56 $ 3,059 $ 3,428 $ 94 $ 111 Interest cost 3,659 3,342 179 165 7,318 6,685 359 330 Expected return on plan assets (6,427) (6,099) — — (12,854) (12,198) — — Amortization of prior service credit — — (84) (117) — — (167) (234) Amortization of net actuarial loss 3,199 5,500 99 131 6,397 11,001 198 262 Net periodic benefit cost 1,960 4,457 241 235 3,920 8,916 484 469 Amount allocated to construction (616) (743) (17) (22) (1,280) (1,469) (35) (43) Net periodic benefit cost charged to expense 1,344 3,714 224 213 2,640 7,447 449 426 Amortization of regulatory balancing account 1,281 1,281 — — 4,082 4,082 — — Net amount charged to expense $ 2,625 $ 4,995 $ 224 $ 213 $ 6,722 $ 11,529 $ 449 $ 426
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The following table presents amounts recognized in accumulated other comprehensive loss (AOCL) and the changes in AOCL related to non-qualified employee benefit plans: Three Months Ended June 30, Six Months Ended June 30, In thousands 2022 2021 2022 2021 Beginning balance $ (11,207) $ (12,681) $ (11,404) $ (12,902) Amounts reclassified from AOCL: Amortization of actuarial losses 268 301 536 602 Total reclassifications before tax 268 301 536 602 Tax benefit (71) (80) (142) (160) Total reclassifications for the period 197 221 394 442 Ending balance $ (11,010) $ (12,460) $ (11,010) $ (12,460)

Income Tax_2

Income Tax	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The effective income tax rate varied from the federal statutory rate due to the following: Three Months Ended June 30, NW Holdings NW Natural In thousands 2022 2021 2022 2021 Income tax at statutory rate (federal) $ 460 $ (210) $ 744 $ 184 State income tax 161 (48) 219 41 Increase (decrease): Differences required to be flowed-through by regulatory commissions (62) 21 (62) 21 Other, net (89) (40) (91) 42 Total provision for income taxes $ 470 $ (277) $ 810 $ 288 Effective income tax rate 21.5 % 27.7 % 22.9 % 32.8 % Six Months Ended June 30, NW Holdings NW Natural In thousands 2022 2021 2022 2021 Income tax at statutory rate (federal) $ 16,243 $ 16,598 $ 16,859 $ 17,123 State income tax 6,674 7,260 6,803 7,366 Increase (decrease): Differences required to be flowed-through by regulatory commissions (3,235) (3,584) (3,235) (3,584) Other, net (289) (30) (294) (65) Total provision for income taxes $ 19,393 $ 20,244 $ 20,133 $ 20,840 Effective income tax rate 25.1 % 25.6 % 25.1 % 25.6 %

Property, Plant and Equipment_2

Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Public Utility Property, Plant, and Equipment [Table Text Block]	The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation: June 30, December 31, In thousands 2022 2021 2021 NW Natural: NGD plant in service $ 3,782,197 $ 3,623,092 $ 3,721,939 NGD construction work in progress 195,118 99,646 135,398 Less: Accumulated depreciation 1,121,444 1,068,603 1,098,715 NGD plant, net 2,855,871 2,654,135 2,758,622 Other plant in service 69,623 66,315 69,332 Other construction work in progress 5,529 5,817 4,971 Less: Accumulated depreciation 21,167 20,140 20,646 Other plant, net 53,985 51,992 53,657 Total property, plant, and equipment, net $ 2,909,856 $ 2,706,127 $ 2,812,279 Other (NW Holdings): Other plant in service $ 59,718 $ 50,148 $ 57,184 Other construction work in progress 17,051 4,774 8,419 Less: Accumulated depreciation 7,944 5,120 6,512 Other plant, net $ 68,825 $ 49,802 $ 59,091 NW Holdings: Total property, plant, and equipment, net $ 2,978,681 $ 2,755,929 $ 2,871,370 NW Natural: Capital expenditures in accrued liabilities $ 44,052 $ 37,968 $ 37,537 NW Holdings: Capital expenditures in accrued liabilities $ 45,079 $ 38,395 $ 38,333 NW Natural Other plant balances include non-utility gas storage assets at the Mist facility and other long-lived assets not related to NGD. NW Holdings Other plant balances include long-lived assets associated with water and wastewater operations and non-regulated activities not held by NW Natural or its subsidiaries.

Investments_2

Investments	6 Months Ended
	Jun. 30, 2022
Investments [Abstract]
Investment [Table Text Block]	Investments include gas reserves, financial investments in life insurance policies, and equity method investments. The following table summarizes other investments: NW Holdings NW Natural June 30, December 31, June 30, December 31, In thousands 2022 2021 2021 2022 2021 2021 Investments in life insurance policies $ 48,735 $ 47,695 $ 48,178 $ 48,735 $ 47,695 $ 48,178 Investments in gas reserves, non-current 24,695 29,852 26,608 24,695 29,852 26,608 Investment in unconsolidated affiliates 22,597 30 14,492 8,056 — — Total other investments $ 96,027 $ 77,577 $ 89,278 $ 81,486 $ 77,547 $ 74,786

Derivative Instruments_2

Derivative Instruments	6 Months Ended
	Jun. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	The following table presents the absolute notional amounts related to open positions on NW Natural derivative instruments: June 30, December 31, In thousands 2022 2021 2021 Natural gas (in therms): Financial 718,965 680,335 618,815 Physical 516,590 419,148 431,628 Foreign exchange $ 7,659 $ 6,477 $ 6,268
Income Statement Presentation of Derivative Instruments	The following table reflects the income statement presentation for the unrealized gains and losses from NW Natural's derivative instruments, which also represents all derivative instruments at NW Holdings: Three Months Ended June 30, 2022 2021 In thousands Natural gas commodity Foreign exchange Natural gas commodity Foreign exchange Benefit (expense) to cost of gas $ (29,332) $ (153) $ 16,323 $ (45) Operating revenues (expense) — — — — Amounts deferred to regulatory accounts on balance sheet 29,332 153 (16,323) 45 Total gain (loss) in pre-tax earnings $ — $ — $ — $ —

Environmental Matters_2

Environmental Matters	6 Months Ended
	Jun. 30, 2022
Environmental Remediation Obligations [Abstract]
Schedule of Environmental Loss Contingencies by Site	The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other current liabilities and other noncurrent liabilities in NW Natural's balance sheet: Current Liabilities Non-Current Liabilities June 30, December 31, June 30, December 31, In thousands 2022 2021 2021 2022 2021 2021 Portland Harbor site: Gasco/Siltronic Sediments $ 6,144 $ 6,658 $ 7,582 $ 40,740 $ 41,652 $ 42,076 Other Portland Harbor 2,313 2,195 2,592 8,613 6,588 9,570 Gasco/Siltronic Upland site 11,050 12,442 15,711 34,352 38,401 36,215 Front Street site 585 1,219 1,100 868 975 811 Oregon Steel Mills — — — 179 179 179 Total $ 20,092 $ 22,514 $ 26,985 $ 84,752 $ 87,795 $ 88,851
Environmental Regulatory Table	The following table presents information regarding the total regulatory asset deferred: June 30, December 31, In thousands 2022 2021 2021 Deferred costs and interest (1) $ 48,814 $ 50,604 $ 45,122 Accrued site liabilities (2) 104,798 110,237 115,773 Insurance proceeds and interest (60,226) (69,730) (59,564) Total regulatory asset deferral (1) $ 93,386 $ 91,111 $ 101,331 Current regulatory assets (3) 6,975 5,688 6,694 Long-term regulatory assets (3) 86,411 85,423 94,636 (1) Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers. (2) Exclude s 3.3% of the Front Street site liability as the OPUC only allows recovery of 96.7% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers. Amounts excluded from regulatory assets were $47 thousand at June 30, 2022, $72 thousand at June 30, 2021, and $62 thousand at December 31, 2021. (3) Environmental costs relate to specific sites approved for regulatory deferral by the OPUC and WUTC. In Oregon, NW Natural earns a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. It also accrues a carrying charge on insurance proceeds for amounts owed to customers. In Washington, neither the cash paid for insurance proceeds received accrue a carrying charge. Current environmental costs represent remediation costs management expects to collect from customers in the next 12 months. Amounts included in this estimate are still subject to a prudence and earnings test review by the OPUC and do not include the $5.0 million tariff rider. The amounts allocable to Oregon are recoverable through NGD rates, subject to an earnings test.

Significant Accounting Polici_4

Significant Accounting Policies - Regulatory Asset Disclosure - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Regulatory Assets [Line Items]
Regulatory Assets, Current	$ 92,803	$ 72,391	$ 60,672
Regulatory Assets, Noncurrent	301,855	314,579	330,710
Other [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Noncurrent	65	40	40
Northwest Natural Gas Company [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	92,803	72,391	60,672
Regulatory Assets, Noncurrent	301,790	314,539	330,670
Northwest Natural Gas Company [Member] | Deferred Derivative Gain (Loss) [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	15,918	10,402	3,393
Regulatory Assets, Noncurrent	9,475	412	453
Northwest Natural Gas Company [Member] | Gas costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	48,218	35,641	29,486
Regulatory Assets, Noncurrent	7,975	15,477	5,742
Northwest Natural Gas Company [Member] | Environmental costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	6,975	6,694	5,688
Regulatory Assets, Noncurrent	86,411	94,636	85,423
Northwest Natural Gas Company [Member] | Decoupling [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	212	969	1,011
Regulatory Assets, Noncurrent	0	0	198
Northwest Natural Gas Company [Member] | Pension balancing [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	7,131	7,131	7,131
Regulatory Assets, Noncurrent	35,150	38,302	40,342
Northwest Natural Gas Company [Member] | Income taxes [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	2,276	2,568	2,345
Regulatory Assets, Noncurrent	11,161	12,609	13,903
Northwest Natural Gas Company [Member] | Pension and other postretirement benefit liabilities [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Noncurrent	110,548	116,440	160,385
Northwest Natural Gas Company [Member] | Other [Member]
Regulatory Assets [Line Items]
Regulatory Assets, Current	12,073	8,986	11,618
Regulatory Assets, Noncurrent	$ 41,070	$ 36,663	$ 24,224

Significant Accounting Polici_5

Significant Accounting Policies - Regulatory Liability Disclosure - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	$ 97,277	$ 112,281	$ 103,210
Regulatory Liability, Noncurrent	658,925	658,332	645,046
Other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	982	982	869
Northwest Natural Gas Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	97,277	112,281	103,210
Regulatory Liability, Noncurrent	657,943	657,350	644,177
Northwest Natural Gas Company [Member] | Gas costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	1,898	70	1,519
Regulatory Liability, Noncurrent	353	250	101
Northwest Natural Gas Company [Member] | Deferred Derivative Gain (Loss) [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	60,652	48,130	46,168
Regulatory Liability, Noncurrent	9,121	10,730	7,912
Northwest Natural Gas Company [Member] | Decoupling [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	14,242	4,475	5,821
Regulatory Liability, Noncurrent	2,557	3,412	652
Northwest Natural Gas Company [Member] | Income taxes [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	7,318	8,192	8,217
Regulatory Liability, Noncurrent	176,358	181,404	182,977
Northwest Natural Gas Company [Member] | Other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	3,406	6,290	2,137
Regulatory Liability, Noncurrent	13,760	13,792	12,850
Northwest Natural Gas Company [Member] | Accrued asset removal costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Noncurrent	455,794	445,952	439,685
Northwest Natural Gas Company [Member] | Asset Optimization Revenue Sharing
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	9,761	45,124	39,348
Regulatory Liability, Noncurrent	$ 0	$ 1,810	$ 0

Supplemental Cash Flow

Supplemental Cash Flow - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 17,209	$ 18,559	$ 20,084
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	30,035	27,120	28,310	$ 35,454
Northwest Natural Gas Company [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	10,267	12,271	11,488
Restricted Cash	12,826	8,561	8,226
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	23,093	20,832	19,714	$ 15,739
Other Current Assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash	$ 12,826	$ 8,561	$ 8,226

Significant Accounting Polici_6

Significant Accounting Policies - Credit Losses - ASU 2016-13 $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($) numberOfLeases	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 1,356	$ 2,018
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	38
Accounts Receivable, Allowance for Credit Loss, Recovery	$ (700)
Number of Net Investments in Sales-Type Leases | numberOfLeases	2
Sales-type Lease, Net Investment in Lease, Allowance for Credit Loss	$ 0
Regulatory Assets, Noncurrent	301,855	314,579	$ 330,710
COVID-19 Related Costs
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Regulatory Assets, Noncurrent	13,400		$ 5,800
Residential [Member]
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Accounts Receivable, Allowance for Credit Loss	850	1,460
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(142)
Accounts Receivable, Allowance for Credit Loss, Recovery	(468)
Commercial [Member]
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Accounts Receivable, Allowance for Credit Loss	120	178
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	52
Accounts Receivable, Allowance for Credit Loss, Recovery	(110)
Industrial [Member]
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Accounts Receivable, Allowance for Credit Loss	150	67
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	110
Accounts Receivable, Allowance for Credit Loss, Recovery	(27)
Accrued unbilled and other [Member]
Accounts Receivable, Noncurrent, Credit Quality Indicator [Line Items]
Accounts Receivable, Allowance for Credit Loss	236	$ 313
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	18
Accounts Receivable, Allowance for Credit Loss, Recovery	$ (95)

Earnings Per Share_2_3

Earnings Per Share - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income	$ 1,715	$ (724)	$ 57,954	$ 58,793
Average common shares outstanding:
Average common shares outstanding - basic (in shares)	34,307	30,664	32,756	30,639
Additional shares for stock-based compensation plans	45	0	49	32
Average common shares outstanding - diluted (in shares)	34,352	30,664	32,805	30,671
Earnings (loss) per share of common stock
Basic (in dollars per share)	$ 0.05	$ (0.02)	$ 1.77	$ 1.92
Diluted (in dollars per share)	$ 0.05	$ (0.02)	$ 1.77	$ 1.92
Antidilutive shares	1	48	1	7

Segment Information - Narrative

Segment Information - Narrative	6 Months Ended
	Jun. 30, 2022
Operating Segments [Member]
Segment Reporting Information [Line Items]
Number of Reportable Segments	1
Oregon [Member] | Northwest Holdings and Northwest Natural [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Percent Of Pre Tax Income From Gas Storage Retained When The Costs Of The Capacity Are Not In Utility Rates	80%
Percent Of Pre Tax Income From Gas Storage Retained When The Costs Of The Capacity Are In Utility Rates	10%
Percent Of Pre Tax Income From Gas Storage Credited To Deferred Regulatory Account	20%
Percent Of Pre Tax Income From Gas Storage Credited To Deferred Regulatory Account When In Rates	90%

Segment Information - Schedule

Segment Information - Schedule of Summarized Financial Information by Segment - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Operating revenues	$ 194,960	$ 148,917	$ 545,261	$ 464,863
Depreciation	28,110	28,144	56,539	56,241
Income from operations	13,539	12,624	101,177	107,330
Total assets	4,100,518	3,783,500	4,100,518	3,783,500	$ 4,064,604
Natural Gas Distribution [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	184,634	139,614	526,032	440,952
Depreciation	27,062	27,273	54,435	54,186
Income from operations	10,575	11,331	96,238	97,818
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	157	(1,381)	55,547	52,544
Capital expenditures	91,122	60,376	155,402	124,368
Total assets	3,875,237	3,587,966	3,875,237	3,587,966	3,846,112
Other Northwest Natural [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,617	4,965	10,843	15,977
Depreciation	266	257	530	513
Income from operations	3,550	2,808	6,438	11,439
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	2,576	1,970	4,602	8,156
Capital expenditures	750	693	787	799
Total assets	54,760	51,466	54,760	51,466	52,260
Northwest Natural Gas Company [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	190,251	144,579	536,875	456,929
Depreciation	27,328	27,530	54,965	54,699
Income from operations	14,125	14,139	102,676	109,257
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	2,733	589	60,149	60,700
Capital expenditures	91,872	61,069	156,189	125,167
Total assets	3,929,997	3,639,432	3,929,997	3,639,432	3,898,372
Other Northwest Holdings [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues	4,709	4,338	8,386	7,934
Depreciation	782	614	1,574	1,542
Income from operations	(586)	(1,515)	(1,499)	(1,927)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	(1,018)	(1,313)	(2,195)	(1,907)
Capital expenditures	7,310	3,337	11,507	4,941
Total assets	170,521	144,068	170,521	144,068	166,232
Northwest Natural Gas Company [Member]
Segment Reporting Information [Line Items]
Operating revenues	190,251	144,579	536,875	456,929
Depreciation	27,328	27,530	54,965	54,699
Income from operations	14,125	14,139	102,676	109,257
Total assets	3,929,997	3,639,432	3,929,997	3,639,432	3,898,372
Northwest Natural Gas Company [Member] | Natural Gas Distribution [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	184,634	139,614	526,032	440,952
Northwest Natural Gas Company [Member] | Other Northwest Natural [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,617	4,965	10,843	15,977
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member]
Segment Reporting Information [Line Items]
Operating revenues	190,251	144,579	536,875	456,929
Parent Company [Member]
Segment Reporting Information [Line Items]
Operating revenues	194,960	148,917	545,261	464,863
Depreciation	28,110	28,144	56,539	56,241
Income from operations	13,539	12,624	101,177	107,330
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	1,715	(724)	57,954	58,793
Capital expenditures	99,182	64,406	167,696	130,108
Total assets	$ 4,100,518	$ 3,783,500	$ 4,100,518	$ 3,783,500	$ 4,064,604

Segment Information - Additiona

Segment Information - Additional Segment Information - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Operating revenues	$ 194,960	$ 148,917	$ 545,261	$ 464,863
Cost of gas	79,720	41,193	225,308	153,403
Environmental remediation	2,267	1,509	6,970	5,286
Operating Segments [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Natural Gas Distribution revenues	179,727	134,849	516,214	431,402
Other regulated services	4,907	4,765	9,818	9,550
Operating revenues	184,634	139,614	526,032	440,952
Cost of gas	79,776	41,249	225,420	153,515
Environmental remediation	2,272	1,509	6,970	5,286
Revenue taxes	8,208	5,650	21,532	18,305
NGD margin	$ 94,378	$ 91,206	$ 272,110	$ 263,846

Equity - Narrative

Equity - Narrative - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	6 Months Ended
	Apr. 01, 2022	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Class of Stock [Line Items]
Par Value (in dollars per share)		$ 0	$ 0	$ 0	$ 0
Shares issued (in shares)		34,754,000	34,754,000	30,672,000	31,129,000
Stock Issued During Period, Shares, New Issues	2,875,000
Proceeds from common stock issued, net	$ 138,600		$ 174,053	$ 0
Avion Water | Other Northwest Holdings [Member]
Class of Stock [Line Items]
Investment balance in Avion					$ 14,500
Northwest Natural Gas Company [Member]
Class of Stock [Line Items]
Repayments of Short-term Debt	$ 130,000
ATM Equity Program
Class of Stock [Line Items]
Par Value (in dollars per share)		$ 0	$ 0
Sale of Stock, Consideration Received on Transaction		$ 25,100	$ 35,200
Sale of Stock, Commissions and Fees Paid		$ 400	$ 700
Stock Issued During Period, Shares, New Issues		482,200	678,101
nwn:AttheMarketEquityProgramEquityAvailableforIssuance		$ 146,200	$ 146,200
Maximum [Member] | Scenario, Plan | ATM Equity Program
Class of Stock [Line Items]
Cumulative Proceeds Received on All Transactions			$ 200,000

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 200,995	$ 133,441	$ 547,824	$ 444,547
Revenues	194,960	148,917	545,261	464,863
Natural Gas Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	190,041	123,739	527,337	419,822
Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3,039	2,805	5,796	5,300
Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,142	817	1,894	7,745
Appliance Center Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,436	1,343	3,153	2,932
Other revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	5,337	4,737	9,644	8,748
Alternative revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	(10,333)	11,083	(11,160)	11,536
Leasing revenue [Member]
Disaggregation of Revenue [Line Items]
Operating leases	4,298	4,393	8,597	8,780
Northwest Natural Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues	190,251	144,579	536,875	456,929
Operating leases	19	25	37	43
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	196,286	129,103	539,438	436,613
Revenues	190,251	144,579	536,875	456,929
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	190,041	123,739	527,337	419,822
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3,039	2,805	5,796	5,300
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,142	817	1,894	7,745
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,436	1,343	3,153	2,932
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Other revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	628	399	1,258	814
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	(10,333)	11,083	(11,160)	11,536
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]
Disaggregation of Revenue [Line Items]
Operating leases	4,298	4,393	8,597	8,780
Operating Segments [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenues	184,634	139,614	526,032	440,952
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	190,669	124,138	528,595	420,636
Revenues	184,634	139,614	526,032	440,952
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	190,041	123,739	527,337	419,822
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Other revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	628	399	1,258	814
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	(10,333)	11,083	(11,160)	11,536
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]
Disaggregation of Revenue [Line Items]
Operating leases	4,298	4,393	8,597	8,780
Operating Segments [Member] | Northwest Natural Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues	190,251	144,579	536,875	456,929
Corporate, Non-Segment [Member] | Other Northwest Natural [Member]
Disaggregation of Revenue [Line Items]
Revenues	5,617	4,965	10,843	15,977
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,617	4,965	10,843	15,977
Revenues	5,617	4,965	10,843	15,977
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,039	2,805	5,796	5,300
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,142	817	1,894	7,745
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,436	1,343	3,153	2,932
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Other revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]
Disaggregation of Revenue [Line Items]
Operating leases	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,709	4,338	8,386	7,934
Revenues	4,709	4,338	8,386	7,934
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Other revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,709	4,338	8,386	7,934
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Alternative revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Leasing revenue [Member]
Disaggregation of Revenue [Line Items]
Operating leases	$ 0	$ 0	$ 0	$ 0

Revenue - Revenue, Remaining Pe

Revenue - Revenue, Remaining Performance Obligation $ in Thousands	Jun. 30, 2022 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Lessor, Sales-type Lease, Term of Contract	30 years
Lessor, Sales-type Lease, Renewal Term	50 years
Revenue, Remaining Performance Obligation, Amount	$ 89,600
Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Refund Liability	0
Other Northwest Natural [Member] | Northwest Natural Gas Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Refund Liability	0
Other Northwest Holdings [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Refund Liability	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	6 months
Revenue, Remaining Performance Obligation, Amount	$ 10,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	1 year
Revenue, Remaining Performance Obligation, Amount	$ 18,600
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	1 year
Revenue, Remaining Performance Obligation, Amount	$ 15,600
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	1 year
Revenue, Remaining Performance Obligation, Amount	$ 13,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	1 year
Revenue, Remaining Performance Obligation, Amount	$ 9,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year	0 years
Revenue, Remaining Performance Obligation, Amount	$ 22,000

Leases - Lease Revenue

Leases - Lease Revenue - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Lessor, Lease, Description [Line Items]
Lessor, Sales-type Lease, Renewal Term	50 years		50 years
Lessor, Sales-type Lease, Term of Contract	30 years		30 years
Residual Value of Leased Asset	$ 4,900	$ 4,500	$ 4,900	$ 4,500	$ 4,700
Lease Revenue [Abstract]
Total lease revenue	100	100	300	300
Operating Leases Payment to be Received [Abstract]
Operating Lease, Payments to be Received, Remainder of Fiscal Year	314		314
Lessor, Operating Lease, Payment to be Received, Year One	127		127
Operating Lease, Payments to be Received, Two Years	128		128
Operating Lease, Payments to be Received, Three Years	120		120
Operating Lease, Payments to be Received, Four Years	92		92
Operating Lease, Payments to be Received, Thereafter	936		936
Total minimum lease payments	1,717		1,717
Total Lease Payments to be Received [Abstract]
Lease Payments to be Received, Remainder of Fiscal Year	8,774		8,774
Lease Payments to be Received, Two Years	16,684		16,684
Lease Payments to be Received, Three Years	15,995		15,995
Lease Payments to be Received, Four Years	15,426		15,426
Lease Payments to be Received, Five Years	14,993		14,993
Lease Payments to be Received, Thereafter	237,756		237,756
Total minimum lease payments	309,628		309,628
Northwest Natural Gas Company [Member]
Lease Revenue [Abstract]
Operating leases	19	25	37	43
Sales-type leases	4,279	4,368	8,560	8,737
Total lease revenue	4,298	$ 4,393	8,597	$ 8,780
Operating Leases Payment to be Received [Abstract]
Operating Lease, Payments to be Received, Remainder of Fiscal Year	289		289
Lessor, Operating Lease, Payment to be Received, Year One	76		76
Operating Lease, Payments to be Received, Two Years	76		76
Operating Lease, Payments to be Received, Three Years	67		67
Operating Lease, Payments to be Received, Four Years	36		36
Operating Lease, Payments to be Received, Thereafter	22		22
Total minimum lease payments	566		566
Total Lease Payments to be Received [Abstract]
Lease Payments to be Received, Remainder of Fiscal Year	8,749		8,749
Lease Payments to be Received, Two Years	16,633		16,633
Lease Payments to be Received, Three Years	15,943		15,943
Lease Payments to be Received, Four Years	15,373		15,373
Lease Payments to be Received, Five Years	14,937		14,937
Lease Payments to be Received, Thereafter	236,842		236,842
Total minimum lease payments	308,477		308,477
Other Northwest Holdings [Member]
Operating Leases Payment to be Received [Abstract]
Operating Lease, Payments to be Received, Remainder of Fiscal Year	25		25
Lessor, Operating Lease, Payment to be Received, Year One	51		51
Operating Lease, Payments to be Received, Two Years	52		52
Operating Lease, Payments to be Received, Three Years	53		53
Operating Lease, Payments to be Received, Four Years	56		56
Operating Lease, Payments to be Received, Thereafter	914		914
Total minimum lease payments	1,151		1,151
Total Lease Payments to be Received [Abstract]
Lease Payments to be Received, Remainder of Fiscal Year	25		25
Lease Payments to be Received, Two Years	51		51
Lease Payments to be Received, Three Years	52		52
Lease Payments to be Received, Four Years	53		53
Lease Payments to be Received, Five Years	56		56
Lease Payments to be Received, Thereafter	914		914
Total minimum lease payments	$ 1,151		$ 1,151
Compressed Natural Gas Lease [Member]
Lessor, Lease, Description [Line Items]
Lessor, Sales-type Lease, Term of Contract	10 years		10 years
Residual Value of Leased Asset	$ 0		$ 0
Variable Lease, Payment			0
North Mist Lease [Member]
Lessor, Lease, Description [Line Items]
Residual Value of Leased Asset	0		0
Variable Lease, Payment			0
Sales-type Lease [Member]
Sales-type Leases Payments to be Received [Abstract]
Sales-type Lease, Payments to be Received, Remainder of Fiscal Year	8,460		8,460
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year One	16,557		16,557
Sales-type Lease, Payments to be Received, Two Years	15,867		15,867
Sales-type Lease, Payments to be Received, Three Years	15,306		15,306
Sales-type Lease, Payments to be Received, Four Years	14,901		14,901
Sales-type Lease, Payments to be Received, Thereafter	236,820		236,820
Total minimum lease payments	307,911		307,911
Less: imputed interest	171,122		171,122
Total leases receivable	136,789		136,789
Sales-type Lease [Member] | Northwest Natural Gas Company [Member]
Sales-type Leases Payments to be Received [Abstract]
Sales-type Lease, Payments to be Received, Remainder of Fiscal Year	8,460		8,460
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year One	16,557		16,557
Sales-type Lease, Payments to be Received, Two Years	15,867		15,867
Sales-type Lease, Payments to be Received, Three Years	15,306		15,306
Sales-type Lease, Payments to be Received, Four Years	14,901		14,901
Sales-type Lease, Payments to be Received, Thereafter	236,820		236,820
Total minimum lease payments	307,911		307,911
Less: imputed interest	171,122		171,122
Total leases receivable	136,789		136,789
Sales-type Lease [Member] | Other Northwest Holdings [Member]
Sales-type Leases Payments to be Received [Abstract]
Sales-type Lease, Payments to be Received, Remainder of Fiscal Year	0		0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year One	0		0
Sales-type Lease, Payments to be Received, Two Years	0		0
Sales-type Lease, Payments to be Received, Three Years	0		0
Sales-type Lease, Payments to be Received, Four Years	0		0
Sales-type Lease, Payments to be Received, Thereafter	0		0
Total minimum lease payments	$ 0		$ 0

Leases - Lease Expense

Leases - Lease Expense - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Lease Expense [Abstract]
Operating Lease, Expense	$ 1,749	$ 1,728	$ 3,483	$ 3,424
Short-term Lease, Cost	$ 416	349	$ 579	569
Minimum [Member]
Operating Lease Terms [Abstract]
Lessee, Operating Lease, Term of Contract	3 months		3 months
Maximum [Member]
Operating Lease Terms [Abstract]
Lessee, Operating Lease, Term of Contract	18 years		18 years
Northwest Natural Gas Company [Member]
Lease Expense [Abstract]
Operating Lease, Expense	$ 1,741	1,710	$ 3,468	3,388
Short-term Lease, Cost	416	349	579	569
Other Northwest Holdings [Member] | Corporate, Non-Segment [Member]
Lease Expense [Abstract]
Operating Lease, Expense	$ 8	$ 18	$ 15	$ 36

Leases - Lease Asset and Liabil

Leases - Lease Asset and Liabilities - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Operating Lease Asset and Liabilities [Abstract]
Operating lease right of use asset	$ 73,754	$ 76,294	$ 73,754	$ 76,294	$ 75,049
Operating lease liabilities current liabilities	1,315	1,228	1,315	1,228	1,296
Operating lease liabilities noncurrent liabilities	78,826	80,088	78,826	80,088	79,468
Total operating lease liabilities	$ 80,141	$ 81,316	$ 80,141	$ 81,316	$ 80,764
Operating Lease, Weighted Average Remaining Lease Term	17 years 8 months 12 days	18 years 8 months 12 days	17 years 8 months 12 days	18 years 8 months 12 days	18 years 2 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	7.20%	7.20%	7.20%	7.20%	7.20%
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Liability, Payments, Due	$ 148,693		$ 148,693
Regulatory Assets, Noncurrent	301,855	$ 330,710	301,855	$ 330,710	$ 314,579
Maturity of Operating Lease Liabilities [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	3,514		3,514
Lessee, Operating Lease, Liability, to be Paid, Year One	7,019		7,019
Lessee, Operating Lease, Liability, Payments, Due Year Two	7,156		7,156
Lessee, Operating Lease, Liability, Payments, Due Year Three	7,191		7,191
Lessee, Operating Lease, Liability, Payments, Due Year Four	7,359		7,359
Lessee, Operating Lease, Liability, Payments, Due after Year Five	116,454		116,454
Lessee, Operating Lease, Liability, Payments, Due	148,693		148,693
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	68,552		68,552
Total operating lease liabilities	80,141	81,316	80,141	81,316	80,764
Operating lease liabilities current liabilities	1,315	1,228	1,315	1,228	1,296
Operating lease liabilities noncurrent liabilities	78,826	80,088	78,826	80,088	79,468
Finance Lease, Liability, Payments, Due Next Twelve Months	100		100
Leases Cash Flow [Abstract]
Operating cash flows from operating leases	1,739	1,734	3,478	3,419
Finance Lease, Principal Payments	307	134	382	678
nwn:Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	(14)
Operating leases		0	0	154
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	120	20	220	94
Finance Leases [Abstract]
Finance Lease, Liability	0		0
Finance Lease, Right-of-Use Asset	2,300	1,900	2,300	1,900	2,100
Other Northwest Holdings [Member] | Corporate, Non-Segment [Member]
Operating Lease Asset and Liabilities [Abstract]
Operating lease right of use asset	48	83	48	83	62
Operating lease liabilities current liabilities	17	35	17	35	23
Operating lease liabilities noncurrent liabilities	37	45	37	45	37
Total operating lease liabilities	54	80	54	80	60
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Liability, Payments, Due	59		59
Maturity of Operating Lease Liabilities [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	12		12
Lessee, Operating Lease, Liability, to be Paid, Year One	6		6
Lessee, Operating Lease, Liability, Payments, Due Year Two	6		6
Lessee, Operating Lease, Liability, Payments, Due Year Three	6		6
Lessee, Operating Lease, Liability, Payments, Due Year Four	6		6
Lessee, Operating Lease, Liability, Payments, Due after Year Five	23		23
Lessee, Operating Lease, Liability, Payments, Due	59		59
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	5		5
Total operating lease liabilities	54	80	54	80	60
Operating lease liabilities current liabilities	17	35	17	35	23
Operating lease liabilities noncurrent liabilities	37	45	37	45	37
Leases Cash Flow [Abstract]
Operating cash flows from operating leases	6	17	12	33
Northwest Natural Gas Company [Member]
Operating Lease Asset and Liabilities [Abstract]
Operating lease right of use asset	73,706	76,211	73,706	76,211	74,987
Operating lease liabilities current liabilities	1,298	1,193	1,298	1,193	1,273
Operating lease liabilities noncurrent liabilities	78,789	80,043	78,789	80,043	79,431
Total operating lease liabilities	80,087	81,236	80,087	81,236	80,704
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Liability, Payments, Due	148,634		148,634
Regulatory Assets, Noncurrent	301,790	330,670	301,790	330,670	314,539
Maturity of Operating Lease Liabilities [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	3,502		3,502
Lessee, Operating Lease, Liability, to be Paid, Year One	7,013		7,013
Lessee, Operating Lease, Liability, Payments, Due Year Two	7,150		7,150
Lessee, Operating Lease, Liability, Payments, Due Year Three	7,185		7,185
Lessee, Operating Lease, Liability, Payments, Due Year Four	7,353		7,353
Lessee, Operating Lease, Liability, Payments, Due after Year Five	116,431		116,431
Lessee, Operating Lease, Liability, Payments, Due	148,634		148,634
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	68,547		68,547
Total operating lease liabilities	80,087	81,236	80,087	81,236	80,704
Operating lease liabilities current liabilities	1,298	1,193	1,298	1,193	1,273
Operating lease liabilities noncurrent liabilities	78,789	80,043	78,789	80,043	79,431
Leases Cash Flow [Abstract]
Operating cash flows from operating leases	1,733	1,717	3,466	3,386
Finance Lease, Principal Payments	307	134	382	678
nwn:Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	(14)
Operating leases		0	0	154
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 120	20	$ 220	94
New Headquarters Lease [Member]
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Term of Contract	20 years		20 years
Regulatory Assets, Noncurrent	$ 6,300	$ 5,000	$ 6,300	$ 5,000	$ 5,700
New Headquarters Lease Renewal Term 2 of 2 [Member] | New Headquarters Lease [Member]
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Renewal Term	7 years		7 years
New Headquarters Lease Renewal Term 1 of 2 [Member] | New Headquarters Lease [Member]
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Renewal Term	7 years		7 years
Maximum [Member]
Commencement of Significant Lease [Abstract]
Lessee, Operating Lease, Term of Contract	18 years		18 years

Stock-Based Compensation_2

Stock-Based Compensation - Long Term Incentive Plan $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)	31,830
Award vesting period	3 years
Unrecognized compensation costs | $	$ 200
Performance Shares | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio, percent of target	0%
Performance Shares | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio, percent of target	200%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Number of RSUs granted in period (in shares)	46,812
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 46.60
Unrecognized compensation costs | $	$ 4,200
A 2021 and 2022 Award | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense | $	$ 0
Target Achieved [Member] | A 2021 Award | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Award Target Share	56,335
Target Achieved [Member] | A 2022 Award | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Award Target Share	56,885

Debt Short-term Debt

Debt Short-term Debt - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Short-term Debt [Line Items]
Short-term debt	$ 222,700	$ 222,700	$ 389,500	$ 240,000
Commercial Paper Maximum Maturity		22 days
Commercial Paper Average Maturity		13 days
Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	78,700	$ 78,700	$ 245,500	$ 198,000
Line of Credit [Member]
Short-term Debt [Line Items]
Short-term debt	$ 144,000	$ 144,000
Debt, Weighted Average Interest Rate	2.70%	2.70%
Commercial Paper [Member] | Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	$ 78,700	$ 78,700
Debt, Weighted Average Interest Rate	2%	2%
364-Day Term Loan, Due 2022 | Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Proceeds from Issuance of Debt		$ 100,000
Debt Instrument, Term	364 days

Long-Term Debt

Long-Term Debt - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2019	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Debt Instrument [Line Items]
Long-term Debt			$ 1,045,881,000	$ 1,044,932,000	$ 975,775,000
Unamortized debt issuance costs			$ 8,031,000	8,309,000	7,446,000
Ratio of Indebtedness to Net Capital			0.527
Northwest Natural Gas Company [Member]
Debt Instrument [Line Items]
Long-term Debt			$ 986,762,000	986,495,000	917,409,000
Unamortized debt issuance costs			$ 7,938,000	$ 8,205,000	$ 7,291,000
Weighted average interest rate			4.40%
Long-Term Debt, Maturity, Year One			$ 0
Northwest Natural Gas Company [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated interest rate			2.80%
Northwest Natural Gas Company [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated interest rate			7.90%
Two-year Term Loan Due 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Term			2 years
Repayments of Debt	$ 35,000,000
Proceeds from Issuance of Debt		$ 35,000,000
Five-year Term Loan Due 2026
Debt Instrument [Line Items]
Stated interest rate			2.30%
Long-term Debt, Term			5 years
Proceeds from Issuance of Debt			$ 55,000,000
Debt Instrument Covenant Consolidated Indebtedness to Capitalization Ratio			70%

Debt Fair Value of Long Term De

Debt Fair Value of Long Term Debt - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Debt Instrument [Line Items]
Gross long-term debt	$ 1,053,912	$ 1,053,241	$ 983,221
Unamortized debt issuance costs	(8,031)	(8,309)	(7,446)
Carrying amount	1,045,881	1,044,932	975,775
Estimated fair value	950,597	1,174,500	1,104,230
Northwest Natural Gas Company [Member]
Debt Instrument [Line Items]
Gross long-term debt	994,700	994,700	924,700
Unamortized debt issuance costs	(7,938)	(8,205)	(7,291)
Carrying amount	986,762	986,495	917,409
Estimated fair value	$ 891,064	$ 1,110,741	$ 1,043,696

Pension and Other Postretirem_3

Pension and Other Postretirement Benefit Costs - Net Periodic Benefit Cost - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 1,529	$ 1,714	$ 3,059	$ 3,428
Interest cost	3,659	3,342	7,318	6,685
Expected return on plan assets	(6,427)	(6,099)	(12,854)	(12,198)
Amortization of net actuarial loss	0	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	3,199	5,500	6,397	11,001
Net periodic benefit cost	1,960	4,457	3,920	8,916
Amount allocated to construction	(616)	(743)	(1,280)	(1,469)
Defined Benefit Plan Net Periodic Benefit Cost Charged To Expense	1,344	3,714	2,640	7,447
Amortization of Regulatory Balancing Account	1,281	1,281	4,082	4,082
Net amount charged to expense	2,625	4,995	6,722	11,529
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	47	56	94	111
Interest cost	179	165	359	330
Expected return on plan assets	0	0	0	0
Amortization of net actuarial loss	(84)	(117)	(167)	(234)
Defined Benefit Plan, Amortization of Gain (Loss)	99	131	198	262
Net periodic benefit cost	241	235	484	469
Amount allocated to construction	(17)	(22)	(35)	(43)
Defined Benefit Plan Net Periodic Benefit Cost Charged To Expense	224	213	449	426
Amortization of Regulatory Balancing Account	0	0	0	0
Net amount charged to expense	$ 224	$ 213	$ 449	$ 426

Pension and Other Postretirem_4

Pension and Other Postretirement Benefit Costs - Amounts Recognized in Accumulated Other Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Beginning balance	$ (11,207)	$ (12,681)	$ (11,404)	$ (12,902)
Amortization of actuarial losses	268	301	536	602
Total reclassifications before tax	268	301	536	602
Tax benefit	(71)	(80)	(142)	(160)
Total reclassifications for the period	197	221	394	442
Ending balance	$ (11,010)	$ (12,460)	$ (11,010)	$ (12,460)

Pension and Other Postretirem_5

Pension and Other Postretirement Benefit Costs - Narrative - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Defined benefit pension plan cash contributions	$ 0	$ (9,600)
Estimated future employer contributions in next fiscal year	0
Employer contributions	$ 5,200	$ 4,700

Income Tax_2_3

Income Tax - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income taxes at statutory rates (federal and state)	$ 460	$ (210)	$ 16,243	$ 16,598
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	161	(48)	6,674	7,260
Differences required to be flowed-through by regulatory commissions	(62)	21	(3,235)	(3,584)
Other, net	(89)	(40)	(289)	(30)
Total provision for income taxes on continuing operations	$ 470	$ (277)	$ 19,393	$ 20,244
Effective tax rate for continuing operations	21.50%	27.70%	25.10%	25.60%
Northwest Natural Gas Company [Member]
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income taxes at statutory rates (federal and state)	$ 744	$ 184	$ 16,859	$ 17,123
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	219	41	6,803	7,366
Differences required to be flowed-through by regulatory commissions	(62)	21	(3,235)	(3,584)
Other, net	(91)	42	(294)	(65)
Total provision for income taxes on continuing operations	$ 810	$ 288	$ 20,133	$ 20,840
Effective tax rate for continuing operations	22.90%	32.80%	25.10%	25.60%

Property, Plant and Equipment_3

Property, Plant and Equipment - USD ($)	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 4,129,236,000	$ 3,997,243,000	$ 3,849,792,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,150,555,000	1,125,873,000	1,093,863,000
Total property, plant, and equipment, net	2,978,681,000	2,871,370,000	2,755,929,000
Natural Gas Distribution [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	3,782,197,000	3,721,939,000	3,623,092,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	195,118,000	135,398,000	99,646,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,121,444,000	1,098,715,000	1,068,603,000
Total property, plant, and equipment, net	2,855,871,000	2,758,622,000	2,654,135,000
Other Northwest Natural [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	69,623,000	69,332,000	66,315,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	5,529,000	4,971,000	5,817,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	21,167,000	20,646,000	20,140,000
Total property, plant, and equipment, net	53,985,000	53,657,000	51,992,000
Northwest Natural Gas Company [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment, net	2,909,856,000	2,812,279,000	2,706,127,000
Property, Plant, Equipment non-cash	44,052,000	37,537,000	37,968,000
Other Northwest Holdings [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	59,718,000	57,184,000	50,148,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	17,051,000	8,419,000	4,774,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	7,944,000	6,512,000	5,120,000
Total property, plant, and equipment, net	68,825,000	59,091,000	49,802,000
Northwest Holdings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, Equipment non-cash	45,079,000	38,333,000	38,395,000
Northwest Natural Gas Company [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	4,052,467,000	3,931,640,000	3,794,870,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,142,611,000	1,119,361,000	1,088,743,000
Total property, plant, and equipment, net	$ 2,909,856,000	$ 2,812,279,000	$ 2,706,127,000

Investments_2_3

Investments $ in Thousands	3 Months Ended
	Jun. 30, 2022 USD ($) numberOfProjects employee numberOfConnections	Jul. 08, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Life Insurance, Corporate or Bank Owned, Amount	$ 48,735		$ 48,178	$ 47,695
Gas reserves, noncurrent	24,695		26,608	29,852
Equity Method Investment, Aggregate Cost	22,597		14,492	30
Other investments	96,027		89,278	77,577
Total cumulative gas reserves investment	188,000
Deferred Taxes Related To Gas Reserves	5,300		6,900	8,800
Gas reserves, current	$ 4,300		5,400	8,400
Investments, Number of RNG Development Projects | numberOfProjects	4
Northwest Natural Gas Company [Member]
Schedule of Equity Method Investments [Line Items]
Life Insurance, Corporate or Bank Owned, Amount	$ 48,735		48,178	47,695
Gas reserves, noncurrent	24,695		26,608	29,852
Equity Method Investment, Aggregate Cost	8,056		0	0
Other investments	81,486		74,786	$ 77,547
Lexington | Northwest Natural Gas Company [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Aggregate Cost	8,100
Deconsolidation, Gain (Loss), Amount	$ 0
Other Northwest Holdings [Member] | Avion Water
Schedule of Equity Method Investments [Line Items]
Ownership percentage of Avion	37.30%
Investment balance in Avion			$ 14,500
Equity Method Investment, Number of Customer Connections | numberOfConnections	15,000
Equity Method Investment, Number of Employees | employee	35
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	$ 10,400
Other Northwest Holdings [Member] | Avion Water | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage of Avion		40.30%
Investment balance in Avion		$ 1,000

Business Combinations Busines_2

Business Combinations Business Combinations	6 Months Ended	12 Months Ended
	Jun. 30, 2022 USD ($) numberOfConnections	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 70,714,000	$ 70,570,000	$ 69,313,000
Goodwill, Impairment Loss	$ 0
Other insignificant acquisitions [Member]
Business Acquisition [Line Items]
Number of Businesses Acquired	1	4

Derivative Instruments Notional

Derivative Instruments Notional Amounts - Northwest Natural Gas Company [Member] therm in Thousands, $ in Thousands	Jun. 30, 2022 USD ($) therm	Dec. 31, 2021 USD ($) therm	Jun. 30, 2021 USD ($) therm
Gas Year 2021-2022
Derivative [Line Items]
TargetHedgeAchieved	79%
Gas Year 2021-2022 | Oregon [Member]
Derivative [Line Items]
TargetHedgeAchieved	82%
Gas Year 2021-2022 | WASHINGTON
Derivative [Line Items]
TargetHedgeAchieved	57%
Financial [Member] | Gas Year 2021-2022 | Oregon [Member]
Derivative [Line Items]
TargetHedgeAchieved	62%
Financial [Member] | Gas Year 2021-2022 | WASHINGTON
Derivative [Line Items]
TargetHedgeAchieved	44%
Physical [Member] | Gas Year 2021-2022 | Oregon [Member]
Derivative [Line Items]
TargetHedgeAchieved	19%
Physical [Member] | Gas Year 2021-2022 | WASHINGTON
Derivative [Line Items]
TargetHedgeAchieved	13%
Natural Gas Therms [Member] | Financial [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	718,965	618,815	680,335
Natural Gas Therms [Member] | Physical [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	516,590	431,628	419,148
Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 7,659	$ 6,268	$ 6,477

Unrealized and Realized Gain_Lo

Unrealized and Realized Gain/Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Derivative [Line Items]
Derivative, Gain on Derivative	$ 21,200	$ 4,200	$ 57,200	$ 9,300
Financial [Member]
Derivative [Line Items]
Incremental Cost or Benefit to Collect or Refund to Customers			0
Northwest Holdings and Northwest Natural [Member] | Natural gas commodity
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	0	0	0	(4)
Northwest Holdings and Northwest Natural [Member] | Foreign exchange
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	0	0	0	0
Northwest Holdings and Northwest Natural [Member] | Benefit (expense) to cost of gas | Natural gas commodity
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	(29,332)	16,323	44,453	(36,805)
Northwest Holdings and Northwest Natural [Member] | Benefit (expense) to cost of gas | Foreign exchange
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	(153)	(45)	(73)	32
Northwest Holdings and Northwest Natural [Member] | Sales [Member] | Natural gas commodity
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	0	0	0	(27)
Northwest Holdings and Northwest Natural [Member] | Sales [Member] | Foreign exchange
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	0	0	0	0
Deferred Derivative Gain (Loss) [Member] | Northwest Holdings and Northwest Natural [Member] | Natural gas commodity
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	29,332	(16,323)	(44,453)	(36,782)
Deferred Derivative Gain (Loss) [Member] | Northwest Holdings and Northwest Natural [Member] | Foreign exchange
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 153	$ 45	$ 73	$ (32)

Derivative Instruments Credit R

Derivative Instruments Credit Rating - USD ($)	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collateral Posted with NW Natural Counterparties [Member]
Derivative [Line Items]
Additional Collateral, Aggregate Fair Value	$ 0	$ 0
Northwest Natural Gas Company [Member]
Derivative [Line Items]
Unrealized Gain (Loss) on Derivatives	46,600,000	54,300,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	47,800,000	51,800,000	$ 51,800,000
Derivative liability	$ 3,400,000	$ 1,600,000	$ 3,800,000

Derivative Instruments Fair Val

Derivative Instruments Fair Value - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Derivative [Line Items]
Derivative, Fair Value, Net	$ 44.4	$ 48	$ 50.2

Environmental Matters_2_3

Environmental Matters	Jun. 30, 2022
Oregon [Member]
Site Contingency [Line Items]
Remediation Recovery Percentage	96.70%
WASHINGTON
Site Contingency [Line Items]
Remediation Recovery Percentage	3.30%

Environmental Matters - Environ

Environmental Matters - Environmental Sites $ in Thousands	1 Months Ended	6 Months Ended
	Jan. 31, 2017 USD ($)	Jun. 30, 2022 USD ($) party property	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)
Site Contingency [Line Items]
Current Liabilities		$ 20,092	$ 26,985	$ 22,514
Non-Current Liabilities		84,752	88,851	87,795
Gasco/Siltronic Sediments
Site Contingency [Line Items]
Current Liabilities		6,144	7,582	6,658
Non-Current Liabilities		40,740	42,076	41,652
Site Contingency, Environmental Remediation Costs Recognized		46,900
Gasco/Siltronic Sediments | Minimum [Member]
Site Contingency [Line Items]
Environmental Exit Costs, Anticipated Cost		46,900
Gasco/Siltronic Sediments | Maximum [Member]
Site Contingency [Line Items]
Environmental Exit Costs, Anticipated Cost		350,000
Portland Harbor Other [Member]
Site Contingency [Line Items]
Current Liabilities		2,313	2,592	2,195
Non-Current Liabilities		$ 8,613	9,570	6,588
Gasco Uplands [Member]
Site Contingency [Line Items]
Site contingency: number of management pieces		2
Gasco/Siltronic Upland [Member]
Site Contingency [Line Items]
Current Liabilities		$ 11,050	15,711	12,442
Non-Current Liabilities		34,352	36,215	38,401
Front Street [Member]
Site Contingency [Line Items]
Current Liabilities		585	1,100	1,219
Non-Current Liabilities		868	811	975
Additional studies and design costs		1,500
Oregon Steel Mills [Member]
Site Contingency [Line Items]
Current Liabilities		0	0	0
Non-Current Liabilities		$ 179	$ 179	$ 179
Portland Harbor [Member]
Site Contingency [Line Items]
Number of potentially responsible parties (more than) | party		100
EPA final feasibility study and proposed remediation plan, clean-up costs, portland harbor	$ 1,050,000
Number of remediation projects | property		2
Portland Harbor [Member] | Minimum [Member]
Site Contingency [Line Items]
Percentage of clean-up costs	(30.00%)
Portland Harbor [Member] | Maximum [Member]
Site Contingency [Line Items]
Percentage of clean-up costs	50%
Yakama Nation [Member] | Portland Harbor Other [Member]
Site Contingency [Line Items]
Trustee Council Members - Number of Claimants		1
Site Contingency, Number of Other Third-Party Defendants		29
NRD liability claim yakama nation		$ 300
Number of Amended Complaints Filed		2

Environmental Matters - Regulat

Environmental Matters - Regulatory Deferred Assets - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Site Contingency [Line Items]
Regulatory Assets, Current	$ 92,803	$ 72,391	$ 60,672
Regulatory Assets, Noncurrent	$ 301,855	$ 314,579	$ 330,710
Remediation Non-recovery Percentage	3.30%	3.30%	3.30%
Annual tariff rider collection	$ 5,000
Annual insurance proceeds to apply against remediation costs	5,000
Total annual remediation expense and interest	$ 10,000
Oregon [Member]
Site Contingency [Line Items]
Remediation Recovery Percentage	96.70%
Front Street [Member] | Environmental costs [Member]
Site Contingency [Line Items]
Accrued site liabilities	$ 47	$ 62	$ 72
Northwest Natural Gas Company [Member]
Site Contingency [Line Items]
Regulatory Assets, Current	92,803	72,391	60,672
Regulatory Assets, Noncurrent	301,790	314,539	330,670
Northwest Natural Gas Company [Member] | Environmental costs [Member]
Site Contingency [Line Items]
Deferred costs and interest	48,814	45,122	50,604
Accrued site liabilities	104,798	115,773	110,237
Insurance proceeds and interest	(60,226)	(59,564)	(69,730)
Regulatory Assets	93,386	101,331	91,111
Regulatory Assets, Current	6,975	6,694	5,688
Regulatory Assets, Noncurrent	$ 86,411	$ 94,636	$ 85,423

Subsequent Events_2

Subsequent Events - Subsequent Event [Member] - Northwest Natural Gas Company [Member] - Note 4780 Series due 2052 $ in Thousands	Jul. 15, 2022 USD ($)
Subsequent Event [Line Items]
Stated interest rate	4.78%
Secured Debt	$ 140,000

Uncategorized Items - nwn-20220

Label	Element	Value
Asset optimization revenue sharing bill credits	nwn_AssetOptimizationRevenueSharingBillCredits	$ (41,102,000)
Asset optimization revenue sharing bill credits	nwn_AssetOptimizationRevenueSharingBillCredits	$ (9,053,000)