Summary of Significant Accounting Policies - Average Depreciation Rates (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Natural gas distribution | Delmarva
Property, Plant and Equipment [Line Items]
Average depreciation rates	2.50%	2.50%	2.50%
Natural gas distribution | Florida
Property, Plant and Equipment [Line Items]
Average depreciation rates	2.20%	2.50%	2.50%
Natural gas transmission | Delmarva
Property, Plant and Equipment [Line Items]
Average depreciation rates	2.70%	2.70%	2.70%
Natural gas transmission | Florida
Property, Plant and Equipment [Line Items]
Average depreciation rates	2.40%	2.40%	2.30%
Natural gas transmission | OHIO
Property, Plant and Equipment [Line Items]
Average depreciation rates	5.00%	5.00%
Electric distribution | Florida
Property, Plant and Equipment [Line Items]
Average depreciation rates	2.40%	2.80%	2.80%