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Percentage of voting equity interest acquired in business combination.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of expense for acquisition-related cost incurred to effect business combination. Includes, but is not limited to, finder's fee; advisory, legal, accounting, valuation, and other professional and consulting fees; and general administrative cost, including cost of maintaining internal acquisition department.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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Amount of acquiree's earnings (loss) since acquisition date of business combination included in consolidated statement of income.

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Amount of identifiable intangible asset acquired in business combination and recognized at acquisition date. Excludes goodwill and financial asset.

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Business Combinations - Narrative (Details)			3 Months Ended				6 Months Ended
Business Combinations - Narrative (Details)	Jun. 02, 2025 USD ($)	Jan. 07, 2025 USD ($)	Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($) business	Jun. 30, 2026 USD ($) customer community	Jun. 30, 2025 USD ($)
Business Combination [Line Items]
Goodwill			$ 371,614,000	$ 370,815,000	$ 370,889,000		$ 371,614,000	$ 370,889,000
Goodwill, impairment loss			0				0
SiEnergy
Business Combination [Line Items]
Goodwill			186,500,000	185,700,000	187,200,000		186,500,000	187,200,000
NWN Water
Business Combination [Line Items]
Goodwill			185,100,000	185,100,000	183,700,000		185,100,000	183,700,000
SiEnergy
Business Combination [Line Items]
Outstanding interest acquired, percentage		100.00%
Cash		$ 271,087,000						271,100,000
Consideration transferred							$ 156,100,000
Customers of business acquired \| customer							88,000
Business combination, acquisition cost						$ 5,300,000
Goodwill		171,107,000
Intangible asset, excluding goodwill			0				$ 0
Business combination, goodwill, expected tax deductible, amount		$ 179,900,000
Statutory tax rate							26.50%
Pines Holdings, Inc.
Business Combination [Line Items]
Outstanding interest acquired, percentage	100.00%
Cash	$ 60,436,000		60,400,000
Customers of business acquired \| customer							8,000
Goodwill	15,448,000
Intangible asset, excluding goodwill			0				$ 0
Business combination, goodwill, expected tax deductible, amount	$ 0
Business combination, communities of business acquired \| community							12
SiEnergy And Pines
Business Combination [Line Items]
Business combination, acquisition cost						5,300,000
Acquiree's revenue since acquisition date, actual			13,500,000		11,500,000		$ 45,200,000	34,200,000
Acquiree's earnings since acquisition date, actual			2,000,000.0		$ 1,000,000.0		11,100,000	$ 6,500,000
Inline Utilities, LLC
Business Combination [Line Items]
Cash				$ 7,200,000
Goodwill			1,000,000.0				1,000,000.0
Business combination, goodwill, expected tax deductible, amount			$ 4,300,000				$ 4,300,000
Other insignificant acquisitions
Business Combination [Line Items]
Cash						$ 1,600,000
Number of businesses acquired \| business						2