Debt Short-term Debt - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Short-term Debt [Line Items]
Short-term debt	$ 94,700	$ 89,780	$ 72,500
Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	31,700	16,780	0
Line of Credit [Member]
Short-term Debt [Line Items]
Short-term debt	$ 63,000	$ 73,000	$ 72,500
Debt, Weighted Average Interest Rate	6.30%	6.40%	5.90%
Commercial Paper [Member] | Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	$ 31,700	$ 16,800	$ 0
Debt, Weighted Average Interest Rate	5.50%	5.50%	0.00%