Supplemental Cash Flow - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 156,616	$ 29,270	$ 108,556
Restricted Cash	14,864	11,694	11,714
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	171,480	40,964	120,270	$ 27,120
Money Market Funds, at Carrying Value	132,600
Northwest Natural Gas Company [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	145,073	12,977	11,386
Restricted Cash	14,838	11,694	11,714
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	159,911	$ 24,671	$ 23,100	$ 20,832
Money Market Funds, at Carrying Value	132,600
Payments of Dividends	$ 25,000

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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