Property, Plant and Equipment - Annual Depreciation Provisions as Percentage of Average Service Life (Details)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.90%	2.87%	2.81%
Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.15%	2.14%	2.13%
Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	7.77%	7.54%	7.31%
Commonwealth Edison Co | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.02%	3.00%	2.94%
PECO Energy Co | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.30%	2.29%	2.28%
PECO Energy Co | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.85%	1.87%	1.84%
PECO Energy Co | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	6.87%	6.31%	6.34%
Baltimore Gas and Electric Company | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.89%	2.82%	2.80%
Baltimore Gas and Electric Company | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.56%	2.53%	2.54%
Baltimore Gas and Electric Company | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.68%	8.20%	7.88%
Pepco Holdings LLC | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.03%	2.96%	2.87%
Pepco Holdings LLC | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.44%	1.45%	1.47%
Pepco Holdings LLC | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	7.18%	8.96%	8.33%
Potomac Electric Power Company | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.51%	2.58%	2.56%
Delmarva Power & Light Company | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.29%	3.08%	2.86%
Delmarva Power & Light Company | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.44%	1.45%	1.47%
Delmarva Power & Light Company | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.79%	10.03%	8.69%
Atlantic City Electric Company | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.66%	3.38%	3.21%