Debt Short-term Debt - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Short-term Debt [Line Items]
Short-term debt	$ 79,000	$ 89,780	$ 41,000
Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	0	16,780	0
Line of Credit [Member]
Short-term Debt [Line Items]
Short-term debt	$ 79,000	$ 73,000	$ 41,000
Debt, Weighted Average Interest Rate	6.40%	6.40%	6.20%
Commercial Paper [Member] \| Northwest Natural Gas Company [Member]
Short-term Debt [Line Items]
Short-term debt	$ 0	$ 16,800	$ 0
Debt, Weighted Average Interest Rate	0.00%	5.50%	0.00%

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
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Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant