Property, Plant and Equipment - Annual Depreciation Provisions as Percentage of Average Service Life (Details)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.87%	2.81%	2.79%
Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.14%	2.13%	2.14%
Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	7.54%	7.31%	7.01%
Commonwealth Edison Co [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.00%	2.94%	2.95%
PECO Energy Co [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.29%	2.28%	2.31%
PECO Energy Co [Member] | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.87%	1.84%	1.85%
PECO Energy Co [Member] | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	6.31%	6.34%	6.39%
Baltimore Gas and Electric Company [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.82%	2.80%	2.69%
Baltimore Gas and Electric Company [Member] | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.53%	2.54%	2.56%
Baltimore Gas and Electric Company [Member] | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.20%	7.88%	7.45%
Pepco Holdings LLC [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.96%	2.87%	2.81%
Pepco Holdings LLC [Member] | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.45%	1.47%	1.50%
Pepco Holdings LLC [Member] | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.96%	8.33%	7.36%
Potomac Electric Power Company [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.58%	2.56%	2.53%
Delmarva Power & Light Company [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.08%	2.86%	2.85%
Delmarva Power & Light Company [Member] | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.45%	1.47%	1.50%
Delmarva Power & Light Company [Member] | Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	10.03%	8.69%	6.72%
Atlantic City Electric Company [Member] | Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.38%	3.21%	3.08%