Valuation Allowances and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Entity Information [Line Items]
Allowance for Doubtful Accounts Receivable, beginning of period	$ 2,018	$ 3,219	$ 673
Valuation Allowances and Reserves, Charged to Cost and Expense	1,081	724	890
Valuation Allowances and Reserves, Charged to Other Accounts	1,810	(219)	2,333
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	1,613	1,706	677
Allowance for Doubtful Accounts Receivable, end of period	3,296	2,018	3,219
Northwest Natural Gas Company [Member]
Entity Information [Line Items]
Allowance for Doubtful Accounts Receivable, beginning of period	1,962	3,107	672
Valuation Allowances and Reserves, Charged to Cost and Expense	920	780	779
Valuation Allowances and Reserves, Charged to Other Accounts	1,810	(219)	2,333
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	1,613	1,706	677
Allowance for Doubtful Accounts Receivable, end of period	$ 3,079	$ 1,962	$ 3,107