Deferred taxes related to gas reserves

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- Definition

Equity Method Investment, Number of Customer Connections

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No definition available.

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- Definition

Equity Method Investment, Number of Employees

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- Definition

Total cumulative gas reserves investment

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of capitalized gas costs of a regulated entity that are expected to be recoverable through rate adjustments within one year or the normal operating cycle, if longer.

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- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the entity's ownership percentage in the investee multiplied by the investee's total equity.

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- Definition

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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Investments - Narrative (Details) $ in Millions	Jun. 30, 2026 USD ($) employee connection	Jan. 31, 2026	Dec. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	Feb. 28, 2025	Jan. 31, 2024	Jun. 30, 2023	Jul. 31, 2022	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Total cumulative gas reserves investment	$ 188.0
Deferred taxes related to gas reserves	1.1		$ 1.8	$ 1.9
Gas reserves, current	$ 2.6		$ 2.6	$ 2.7
Avion Water \| NWN Water
Schedule of Equity Method Investments [Line Items]
Ownership percentage of Avion		50.00%			47.90%	45.60%	43.10%	40.30%	37.30%
Equity method investment, underlying equity in net assets									$ 14.5
Equity method investment, number of customer connections \| connection	17,000
Equity method investment, number of employees \| employee	41
Equity method investment, difference between carrying amount and underlying equity	$ 10.1