SEGMENT INFORMATION (Details) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
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Jun. 30, 2026
USD ($)
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Jun. 30, 2025
USD ($)
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Jun. 30, 2026
USD ($)
numberOfSegments
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Jun. 30, 2025
USD ($)
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Dec. 31, 2025
USD ($)
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| Segment Reporting [Abstract] | |||||
| Number of reportable segments | numberOfSegments | 2 | ||||
| Segment information | |||||
| External revenues | $ 407.5 | $ 410.5 | $ 971.8 | $ 909.2 | |
| Fuel and purchased power | 87.4 | 90.8 | 199.5 | 188.3 | |
| Cost of natural gas sold | 29.3 | 32.7 | 164.3 | 125.4 | |
| Other operation and maintenance | 129.4 | 121.8 | 249.5 | 241.1 | |
| Depreciation and amortization | 69.4 | 66.7 | 138.0 | 132.5 | |
| Property and revenue taxes | 12.7 | 11.0 | 25.8 | 22.4 | |
| Other income, net | 9.5 | 4.2 | 17.0 | 8.5 | |
| Interest expense | 23.9 | 24.2 | 47.7 | 48.2 | |
| Income tax expense | 9.6 | 12.3 | 24.8 | 28.8 | |
| Net income | 55.3 | 55.2 | 139.2 | 131.0 | |
| Capital expenditures | 172.3 | 129.0 | 319.9 | 253.6 | |
| Equity method investments | 19.1 | 16.8 | 19.1 | 16.8 | |
| Total assets | 8,224.8 | 7,615.6 | 8,224.8 | 7,615.6 | $ 8,054.6 |
| Utility | |||||
| Segment information | |||||
| External revenues | 407.5 | 410.5 | 971.8 | 909.2 | |
| Fuel and purchased power | 87.4 | 90.8 | 199.5 | 188.3 | |
| Cost of natural gas sold | 29.3 | 32.7 | 164.3 | 125.4 | |
| Other operation and maintenance | 129.4 | 121.8 | 249.5 | 241.1 | |
| Depreciation and amortization | 69.4 | 66.7 | 138.0 | 132.5 | |
| Property and revenue taxes | 12.7 | 11.0 | 25.8 | 22.4 | |
| Other income, net | 8.8 | 3.7 | 15.7 | 7.5 | |
| Interest expense | 23.9 | 24.2 | 47.7 | 48.2 | |
| Income tax expense | 9.4 | 12.2 | 24.4 | 28.6 | |
| Net income | 54.8 | 54.8 | 138.3 | 130.2 | |
| Capital expenditures | 172.3 | 129.0 | 319.9 | 253.6 | |
| Equity method investments | 0.9 | 0.9 | 0.9 | 0.9 | |
| Total assets | 8,206.6 | 7,599.7 | 8,206.6 | 7,599.7 | |
| Other | |||||
| Segment information | |||||
| External revenues | 0.0 | 0.0 | 0.0 | 0.0 | |
| Fuel and purchased power | 0.0 | 0.0 | 0.0 | 0.0 | |
| Cost of natural gas sold | 0.0 | 0.0 | 0.0 | 0.0 | |
| Other operation and maintenance | 0.0 | 0.0 | 0.0 | 0.0 | |
| Depreciation and amortization | 0.0 | 0.0 | 0.0 | 0.0 | |
| Property and revenue taxes | 0.0 | 0.0 | 0.0 | 0.0 | |
| Other income, net | 0.7 | 0.5 | 1.3 | 1.0 | |
| Interest expense | 0.0 | 0.0 | 0.0 | 0.0 | |
| Income tax expense | 0.2 | 0.1 | 0.4 | 0.2 | |
| Net income | 0.5 | 0.4 | 0.9 | 0.8 | |
| Capital expenditures | 0.0 | 0.0 | 0.0 | 0.0 | |
| Equity method investments | 18.2 | 15.9 | 18.2 | 15.9 | |
| Total assets | $ 18.2 | $ 15.9 | $ 18.2 | $ 15.9 | |
| X | ||||||||||
- Definition Amount of asset recognized for present right to economic benefit. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of interest expense classified as other. No definition available.
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of income (expense) related to nonoperating activities, classified as other. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of expenditure for addition to long-lived assets included in determination of segment assets by chief operating decision maker (CODM) or otherwise regularly provided to CODM. Excludes expenditure for addition to financial instrument, long-term customer relationship of financial institution, mortgage and other servicing rights, deferred policy acquisition cost, and deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- References No definition available.
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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. No definition available.
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- Definition All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fuel and purchased power costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No definition available.
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- Details
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- Details
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