Rates and Other Regulatory Activities - Additional Information (Detail) $ in Thousands		12 Months Ended
		Dec. 31, 2025 USD ($) Dekatherm	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2026 USD ($)
Rates and Other Regulatory Activities [Line Items]
Regulatory Assets		$ 104,000	$ 101,300
Revenues		930,000	787,200	$ 670,600
RSAM		25,000
Regulatory Liabilities		202,600	200,100
Gas Utility Access and Replacement Directive Related Capital Expenditures		205,000
RSAM Adjustment		$ 15,500	$ 5,100
Number of Miles of Distribution Mains		150	160
Safety, Access, and Facility Enhancement Capital Expenditures		$ 205,000
Total Projected Capital Expenditures		255,000
Depreciation Study Impact		1,200
Safety, Access, and Facility Enhancement Additional Capital Expenditures		50,000
Depreciation Reserve Amount		6,800
Storm reserve
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities	[1]	2,300	$ 2,100
TCJA
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities		83,400	84,600
Underrecovered purchased fuel costs
Rates and Other Regulatory Activities [Line Items]
Regulatory Assets	[2],[3]	19,600	9,700
Maryland Natural Gas Distribution Businesses [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		6,900
Maryland Natural Gas [Member]
Rates and Other Regulatory Activities [Line Items]
Annual Rate Case Recovery		$ 2,600
Rate Case ROE		11.50%
Incremental Rate Case Recovery		$ 900
Total Rate Case Recovery		3,500
Florida City Gas
Rates and Other Regulatory Activities [Line Items]
Total Base Revenue		23,300
Rate Increase		14,100
Base Rate Increase Base - SAFE investments transfer to base rates		5,300
Base Rate Increase - liquefied natural gas facility		3,800
Florida City Gas | Storm reserve
Rates and Other Regulatory Activities [Line Items]
Regulatory Liabilities		800
Delaware natural gas division [Member]
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		12,100
Annual Rate Case Recovery		$ 6,100	2,500
Rate Case ROE		11.50%
Florida Electric Distribution
Rates and Other Regulatory Activities [Line Items]
Permanent Rates		$ 8,600	$ 12,600
Annual Rate Case Recovery		$ 1,800
Cost Recovery Storm Protection Plan					$ 20,400
Rate Case ROE		11.30%
Deferred Rate Case Recovery		$ 1,000
Step Up Rate Case Recovery		$ 700
Eastern Shore Gas Company [Member]
Rates and Other Regulatory Activities [Line Items]
Number of Miles of Distribution Mains			5.5
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
FL Mandatory Relocates | Florida Natural Gas Distribution [Member]
Rates and Other Regulatory Activities [Line Items]
Projected Revenue		$ 500
FL Mandatory Relocates | Florida City Gas
Rates and Other Regulatory Activities [Line Items]
Projected Revenue		1,000
Regulated Energy [Member]
Rates and Other Regulatory Activities [Line Items]
Revenues		$ 687,800	$ 583,400	$ 473,600
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.