Rates and Other Regulatory Activities - Additional Information (Detail)		12 Months Ended
		Dec. 31, 2024 USD ($) Dekatherm	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2025 USD ($)
Rates and Other Regulatory Activities [Line Items]
Regulatory Assets		$ 101,300,000	$ 115,900,000
Revenues		787,200,000	670,600,000	$ 680,700,000
RSAM		25,000,000
Regulatory Liabilities		200,100,000	209,000,000.0
Gas Utility Access and Replacement Directive Related Capital Expenditures		205,000,000.0
RSAM Adjustment		$ 15,500,000	$ 5,100,000
Number of Miles of Distribution Mains		150	160
Safety, Access, and Facility Enhancement Capital Expenditures		$ 205,000,000.0
Total Projected Capital Expenditures		255,000,000.0
Depreciation Study Impact		1,200,000
Safety, Access, and Facility Enhancement Additional Capital Expenditures		50,000,000.0
Storm reserve
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities	[1]	2,100,000	$ 1,900,000
TCJA
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities		84,600,000	85,800,000
Underrecovered purchased fuel costs
Rates and Other Regulatory Activities [Line Items]
Regulatory Assets	[2],[3]	9,700,000	13,700,000
Maryland Natural Gas Distribution Businesses [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		6,900,000
Maryland Natural Gas [Member]
Rates and Other Regulatory Activities [Line Items]
Annual Rate Case Recovery		$ 2,600,000
Rate Case ROE		11.50%
West Palm Beach Florida | Minimum [Member]
Rates and Other Regulatory Activities [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss		$ 2,800,000
West Palm Beach Florida | Maximum [Member]
Rates and Other Regulatory Activities [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss		5,200,000
Florida City Gas
Rates and Other Regulatory Activities [Line Items]
Total Base Revenue		23,300,000
Rate Increase		14,100,000
Base Rate Increase Base - SAFE investments transfer to base rates		5,300,000
Base Rate Increase - liquefied natural gas facility		3,800,000
Florida City Gas | Storm reserve
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities		800,000
Delaware natural gas division [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		12,100,000
Annual Rate Case Recovery		$ 2,500,000
Rate Case ROE		11.50%
Florida Electric Distribution
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		$ 12,600,000
Annual Rate Case Recovery		$ 1,800,000
Cost Recovery Storm Protection Plan					$ 20,400,000
Rate Case ROE		11.30%
Newberry Expansion | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		8,000
East Coast Reinforcement Projects: Boynton Beach | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		15,000
East Coast Reinforcement Projects: New Smyrna Beach | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		3,400
Central Florida Reinforcement Projects: Plant City | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		5,000
Central Florida Reinforcement Projects: Lake Mattie | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		8,700
St. Cloud Project Amendment | Peninsula Pipeline Company
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		10,000
Regulated Energy [Member]
Rates and Other Regulatory Activities [Line Items]
Revenues		$ 583,400,000	$ 473,600,000	$ 429,400,000
Elkton Gas [Member] | Regulated Energy [Member]
Rates and Other Regulatory Activities [Line Items]
Number of customers acquired through acquisition		7,000

[1] We have storm reserves in our Florida regulated energy operations that allow us to collect through rates amounts to be used against general claims, storm restoration costs and other losses as they are incurred.

[2] Includes amounts being recovered over a three-year period primarily concentrated in our electric division. Per Florida PSC approval, our electric division was allowed to recover these amounts over an extended period of time in an effort to reduce the impact of increased commodity prices to our customers. Recovery of these costs began in January 2023.

[3] We are allowed to recover the asset or are required to pay the liability in rates. We do not earn an overall rate of return on these assets.