Income Taxes - Reconciliation to Effective Tax Rate (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	6.40%	6.00%
Plant basis differences	(3.80%)	(4.00%)
Excess deferred tax amortization	(14.70%)	(6.30%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Tax credits	(0.40%)	(0.50%)
Other	0.30%	0.60%
Effective income tax rate	8.70%	16.70%
Commonwealth Edison Co
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	7.80%	7.90%
Plant basis differences	(0.90%)	(0.30%)
Excess deferred tax amortization	(18.90%)	(5.70%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Tax credits	(0.30%)	(0.30%)
Other	0.40%	0.30%
Effective income tax rate	9.00%	22.80%
PECO Energy Co
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	(0.60%)	(1.40%)
Plant basis differences	(12.20%)	(15.20%)
Excess deferred tax amortization	(2.30%)	(2.40%)
Amortization of investment tax credit, including deferred taxes on basis difference	0.00%	0.00%
Tax credits	0.00%	0.00%
Other	0.40%	0.40%
Effective income tax rate	6.30%	2.40%
Baltimore Gas and Electric Company
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	6.30%	6.40%
Plant basis differences	(1.20%)	(0.70%)
Excess deferred tax amortization	(17.50%)	(5.40%)
Amortization of investment tax credit, including deferred taxes on basis difference	0.00%	(0.10%)
Tax credits	(0.40%)	(0.50%)
Other	0.10%	(0.10%)
Effective income tax rate	8.30%	20.60%
Pepco Holdings LLC
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	6.40%	6.00%
Plant basis differences	(0.90%)	(1.80%)
Excess deferred tax amortization	(6.80%)	(7.00%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Tax credits	(0.30%)	(0.40%)
Other	(0.10%)	0.30%
Effective income tax rate	19.20%	18.00%
Potomac Electric Power Company
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	6.20%	5.40%
Plant basis differences	(1.30%)	(2.50%)
Excess deferred tax amortization	(9.90%)	(8.40%)
Amortization of investment tax credit, including deferred taxes on basis difference	0.00%	0.00%
Tax credits	(0.30%)	(0.40%)
Other	0.00%	0.50%
Effective income tax rate	15.70%	15.60%
Delmarva Power and Light Company
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	6.20%	6.30%
Plant basis differences	(1.10%)	(1.00%)
Excess deferred tax amortization	(5.40%)	(8.80%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Tax credits	(0.30%)	(0.40%)
Other	0.20%	(0.30%)
Effective income tax rate	20.50%	16.70%
Atlantic City Electric Company
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	7.10%	6.90%
Plant basis differences	0.10%	(0.90%)
Excess deferred tax amortization	(1.30%)	(2.00%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Tax credits	(0.30%)	(0.30%)
Other	1.00%	0.40%
Effective income tax rate	27.50%	25.00%