Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock Including APIC [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Northwest Natural Gas Company [Member]	Northwest Natural Gas Company [Member] Northwest Natural Gas Company Consolidated [Member]	Northwest Natural Gas Company [Member] Common Stock Including APIC [Member]	Northwest Natural Gas Company [Member] Retained Earnings [Member]	Northwest Natural Gas Company [Member] Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2019	$ 865,999	$ 558,282	$ 318,450	$ (10,733)		$ 822,196	$ 319,557	$ 513,372	$ (10,733)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	74,612	0	76,781	(2,169)	$ 68,394	68,394	0	70,563	(2,169)
Dividends on common stock	(58,708)	0	(58,708)	0		(55,355)	0	(55,355)	0
Stockholders' Equity, Other						(51)	(51)	0	0
Shares issued pursuant to equity based plans	4,361	4,361	0	0
Capital contributions					0	116,009	116,009	0	0
Shares issued pursuant to equity based plans	2,469	(2,469)	0	0
Ending Balance at Dec. 31, 2020	$ 888,733	565,112	336,523	(12,902)		835,184	319,506	528,580	(12,902)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common stock (in dollars per share)	$ 1.91
Comprehensive income (loss)	$ 80,164	0	78,666	1,498	82,670	82,670	0	81,172	1,498
Dividends on common stock	(59,410)	0	(59,410)	0		(56,056)	0	(56,056)	0
Stock-based compensation	3,615	3,615	0	0
Shares issued pursuant to equity based plans	4,543	4,543	0	0
Capital contributions					116,009
Issuance of common stock, net of issuance costs	17,501	17,501	0	0
Ending Balance at Dec. 31, 2021	$ 935,146	590,771	355,779	(11,404)		977,807	435,515	553,696	(11,404)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common stock (in dollars per share)	$ 1.92
Comprehensive income (loss)	$ 91,422	0	86,303	5,119	96,554	96,554	0	91,564	4,990
Dividends on common stock	(65,609)	0	(65,609)	0		(62,667)	0	(62,667)	0
Stock-based compensation	3,228	3,228	0	0
Shares issued pursuant to equity based plans	2,978	2,978	0	0
Capital contributions					$ 179,388	179,388	179,388	0	0
Issuance of common stock, net of issuance costs	208,276	208,276	0	0
Ending Balance at Dec. 31, 2022	$ 1,175,441	$ 805,253	$ 376,473	$ (6,285)		$ 1,191,082	$ 614,903	$ 582,593	$ (6,414)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common stock (in dollars per share)	$ 1.93