Rates and Other Regulatory Activities - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($) Dekatherm	Sep. 30, 2023	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities	$ (84,900,000)	$ (84,900,000)				$ 85,800,000
Gas Utility Access and Replacement Directive Related Capital Expenditures		205,000,000
RSAM					$ 25,000,000
Safety, Access, and Facility Enhancement Capital Expenditures		50,000,000
Total Projected Capital Expenditures		255,000,000
Safety, Access, and Facility Enhancement Capital Expenditures		$ 205,000,000
Number of Miles of Distribution Mains		150	160
Environmental liabilities	2,441,000	$ 2,441,000				$ 2,607,000
Depreciation Study Impact	1,200,000	1,200,000
Maryland Natural Gas [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates	$ 6,900,000	6,900,000
Annual Rate Case Recovery		$ 2,600,000
Rate Case ROE	11.50%	11.50%
Florida City Gas
Rates and Other Regulatory Activities [Line Items]
Total Base Rate Increase					23,300,000
Base Rate Increase - liquefied natural gas facility					3,800,000
Base Rate Increase Base - SAFE investments transfer to base rates					5,300,000
Base Rate Increase					14,100,000
RSAM Adjustment	$ 3,200,000	$ (8,900,000)
Florida City Gas | Storm Reserve
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities					800,000
Florida Electric Distribution
Rates and Other Regulatory Activities [Line Items]
Permanent Rates	$ 12,600,000	12,600,000
Annual Rate Case Recovery		$ 1,800,000
Cost Recovery Storm Protection Plan				$ 20,400,000	13,600,000
Rate Case ROE	11.30%	11.30%
West Palm Beach Florida [Member] | Minimum [Member]
Rates and Other Regulatory Activities [Line Items]
Estimated costs of remediation range, minimum		$ 3,000,000
West Palm Beach Florida [Member] | Maximum [Member]
Rates and Other Regulatory Activities [Line Items]
Estimated costs of remediation range, minimum		5,400,000
Delaware natural gas division [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates	$ 12,100,000	12,100,000
Annual Rate Case Recovery		$ 2,500,000
Rate Case ROE	11.50%	11.50%
Florida Public Utilities Company [Member]
Rates and Other Regulatory Activities [Line Items]
Environmental liabilities	$ 3,400,000	$ 3,400,000			$ 3,600,000
Eastern Shore Gas Company [Member]
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities	$ 34,200,000	$ 34,200,000
Newberry Expansion | Peninsula Pipeline Company [Member]
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 [Member]
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 [Member]
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		3,400
Central Florida Reinforcement Projects | Peninsula Pipeline Company [Member]
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		8,700
Central Florida Reinforcement Projects: Plant City | Peninsula Pipeline Company [Member]
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		5,000
St. Cloud Project Amendment | Peninsula Pipeline Company [Member]
Rates and Other Regulatory Activities [Line Items]
Additional Firm Natural Gas Transportation Deliverability | Dekatherm		10,000