Summary of Significant Accounting Policies - Summary of Property, Plant and Equipment by Classification (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) mi	Dec. 31, 2023 USD ($)
Property, Plant and Equipment [Line Items]
Contributions in Aid of Construction	$ 5.9	$ 4.2
Public Utilities, Allowance for Funds Used During Construction, Description	$ 1.4
Number of Months to Establish ROU Asset and Liability	12 months
Property, plant and equipment
Total property, plant and equipment	$ 3,155.4	2,859.6
Less: Accumulated depreciation and amortization	(567.6)	(516.4)
Net property, plant and equipment	2,735.9	2,456.4
Construction Work in Progress	148.1	113.2
Jointly Owned Pipeline [Member]
Property, plant and equipment
Net property, plant and equipment	28.4
Accumulated Depreciation, Depletion and Amortization, Sale or Disposal of Property, Plant and Equipment	2.8	2.2
Natural Gas Distribution [Member] | Delmarva and Florida [Member]
Property, plant and equipment
Total property, plant and equipment	1,679.3	1,486.8
Natural Gas Transmission [Member] | Delmarva Peninsula, Pennsylvania and Florida [Member]
Property, plant and equipment
Total property, plant and equipment	819.5	788.2
Natural Gas Transmission [Member] | OHIO
Property, plant and equipment
Total property, plant and equipment	139.2	134.2
Electric distribution | Florida
Property, plant and equipment
Total property, plant and equipment	163.0	143.5
Propane Operations [Member] | Mid-Atlantic and Florida [Member]
Property, plant and equipment
Total property, plant and equipment	201.6	194.9
Electricity and Steam Generation [Member] | Florida
Property, plant and equipment
Total property, plant and equipment	37.4	37.1
Mobile CNG Utility and Pipeline Solutions [Member] | Florida
Property, plant and equipment
Total property, plant and equipment	52.8	40.6
Other
Property, plant and equipment
Total property, plant and equipment	29.9	30.3
Other unregulated energy | Other [Member]
Property, plant and equipment
Total property, plant and equipment	$ 32.7	$ 4.0
Natural Gas Operations
Property, plant and equipment
Miles Of Natural Gas Pipeline | mi	26