Basis Of Accounting Presentation [Line Items]

No definition available.

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- Definition

Number of customers

+ References

No definition available.

+ Details

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- Definition

Pre tax rate for allowance for funds used during construction

+ References

No definition available.

+ Details

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- Definition

The excess of replacement or current cost over the stated LIFO (last in first out) inventory value when the LIFO inventory method is utilized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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- Definition

The amount of LIFO (last in first out) inventory present at the reporting date when inventory is also valued using different valuation methods.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483489/210-10-50-1

+ Details

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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No definition available.

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- Definition

The amount of weighted average cost inventory present at the reporting date when inventory is valued using different valuation methods.

+ References

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Nature of Operations And Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022	Jun. 17, 2023 Rate
Basis Of Accounting Presentation [Line Items]
Number of customers	3,800,000
Pre-tax rate for allowance for funds used during construction	4.80%	3.90%	3.40%
Inventory valued using LIFO	$ 43.8	$ 43.9
Excess of replacement over LIFO value	(12.8)	(22.5)
Inventory valued using the weighted average cost methodology	$ 135.8	$ 222.0
NIPSCO Holdings II
Basis Of Accounting Presentation [Line Items]
Subsidiary, Ownership Percentage, Parent \| Rate				19.90%