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Rate and Regulatory Matters (Details) $ in Millions			1 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jan. 01, 2026 USD ($)	Jan. 01, 2025 USD ($)	Oct. 31, 2025 USD ($) customer	Jul. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	May 31, 2025 USD ($) entity	Feb. 28, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	Sep. 30, 2025 USD ($) unit	Dec. 31, 2024 USD ($)
Subsequent Event | Tidewater | Pinewood Acres Water Utility Assets
Regulatory Asset [Line Items]
Requested purchase of assets			$ 0.2
Number of customers served | customer			350
DSIC
Regulatory Asset [Line Items]
Approved increase amount in revenues												$ 2.3
DSIC | Subsequent Event
Regulatory Asset [Line Items]
Requested increase in annual base revenues			$ 0.9
NJBPU
Regulatory Asset [Line Items]
Number of entities seeking permissions for a corporate reorganization | entity						3
Requested increase in annual base revenues					$ 24.9
Requested increase in annual base revenues percentage					19.30%
NJBPU | RESIC
Regulatory Asset [Line Items]
Period for requested recovery of costs				3 years
Period for surcharge filings				6 months
Maximum value of costs to be recovered				$ 3.8
Maximum percentage of costs to be recovered				2.50%
NJBPU | DSIC
Regulatory Asset [Line Items]
Period for requested recovery of costs				3 years
Period for surcharge filings				6 months
Maximum value of costs to be recovered				$ 7.6
Maximum percentage of costs to be recovered				5.00%
Approved increase amount in revenues						$ 1.1
NJBPU | PWAC
Regulatory Asset [Line Items]
Approved recovery of costs							$ 0.5
NJBPU | LSLR
Regulatory Asset [Line Items]
Approved recovery of costs										$ 0.3
Recovering costs											$ 0.6
DEPSC | Tidewater
Regulatory Asset [Line Items]
Approved increase amount in revenues				$ 5.5
Approved recovery of costs								$ 2.1
Authorized return on common equity rate				9.50%
Authorized common equity ratio				53.50%
Amount spent to identify and inventory lead service lines											$ 1.8
DEPSC | Tidewater | Forecast
Regulatory Asset [Line Items]
Refund of excess deferred income taxes									$ 1.1
Refund of interest on excess deferred income taxes									$ 0.4
DEPSC | Southern Shores
Regulatory Asset [Line Items]
Approved increase amount in revenues		$ 0.1
Number of unit condominium community entity provides water service to | unit											2,200
Approved increase percentage in rates		6.51%										3.00%
DEPSC | Southern Shores | Forecast
Regulatory Asset [Line Items]
Approved increase amount in revenues	$ 0.1
Approved increase percentage in rates	4.89%

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

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