Debt Short-term Debt - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Short-term Debt [Line Items]
Short-term debt	$ 332,500	$ 389,500	$ 236,225
Commercial Paper Maximum Maturity	39 days
Commercial Paper Average Maturity	17 days
Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	$ 188,500	$ 245,500	$ 175,225
Line of Credit [Member]
Short-term Debt [Line Items]
Short-term debt	$ 144,000
Debt, Weighted Average Interest Rate	1.50%
Commercial Paper [Member] | Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	$ 188,500
Debt, Weighted Average Interest Rate	0.80%
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