Pension and Other Postretirement Benefits Costs - Schedule of Fair Value of Plan Assets - Pension Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	$ 280,306	$ 399,217
Northwest Natural Gas Company [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	280,304	399,217
Total Pension Asset Investments Net Of Receivables And Payables	280,304	399,217
Accrued interest and dividend income	7,703	0
Total receivables	7,703	0
Due to broker for securities purchased	(7,701)	0
Northwest Natural Gas Company [Member] | United States Equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	68,729	121,090
Northwest Natural Gas Company [Member] | Non-U.S. equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	90,504	123,534
Northwest Natural Gas Company [Member] | Liability hedging [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	94,823	118,464
Northwest Natural Gas Company [Member] | Opportunistic [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	23,903	33,808
Northwest Natural Gas Company [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	2,345	2,321
Northwest Natural Gas Company [Member] | Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Total Pension Asset Investments Net Of Receivables And Payables	26,677	35,456
Northwest Natural Gas Company [Member] | Level 1 [Member] | United States Equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 1 [Member] | Non-U.S. equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	26,677	35,456
Northwest Natural Gas Company [Member] | Level 1 [Member] | Liability hedging [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 1 [Member] | Opportunistic [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Total Pension Asset Investments Net Of Receivables And Payables	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member] | United States Equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member] | Non-U.S. equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member] | Liability hedging [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member] | Opportunistic [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Total Pension Asset Investments Net Of Receivables And Payables	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member] | United States Equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member] | Non-U.S. equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member] | Liability hedging [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member] | Opportunistic [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	0	0
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Total Pension Asset Investments Net Of Receivables And Payables	253,627	363,761
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | United States Equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	68,729	121,090
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Non-U.S. equity [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	63,827	88,078
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Liability hedging [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	94,823	118,464
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Opportunistic [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	23,903	33,808
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Plan Assets, Amount	$ 2,345	$ 2,321