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