Regulatory Matters - Schedule of Regulatory Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Regulatory Assets [Line Items]
Regulatory Assets	$ 10,913	$ 9,678
Regulatory Liabilities	9,965	9,549
Current regulatory assets	2,215	1,641
Noncurrent regulatory assets	8,698	8,037
Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	109	122
Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	127	160
Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	159	151
Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	673	843
COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	41	58
DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	3	37
Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	759	606
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	114	90
Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	787	271
Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	89	115
Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	98	241
Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	631	560
Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	1,691	1,434
Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	486	521
Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	35	44
MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	315	318
Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	112
Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	2,254	1,867
Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	637	769
Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	827	782
Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	134	85
Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	75	37
Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	112	71
Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	176	106
ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	58
Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	59	19
Other
Regulatory Assets [Line Items]
Regulatory Assets	352	371
Commonwealth Edison Co
Regulatory Assets [Line Items]
Regulatory Assets	4,129	3,442
Regulatory Liabilities	7,684	7,139
Current regulatory assets	1,335	775
Noncurrent regulatory assets	2,794	2,667
Commonwealth Edison Co | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	28	48
Commonwealth Edison Co | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	104	99
Commonwealth Edison Co | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	673	843
Commonwealth Edison Co | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	11	20
Commonwealth Edison Co | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	787	271
Commonwealth Edison Co | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	89	115
Commonwealth Edison Co | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	1,691	1,434
Commonwealth Edison Co | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	286	293
Commonwealth Edison Co | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
Commonwealth Edison Co | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	134	85
Commonwealth Edison Co | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	78	38
Commonwealth Edison Co | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	58
Commonwealth Edison Co | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Commonwealth Edison Co | Other
Regulatory Assets [Line Items]
Regulatory Assets	190	196
PECO Energy Co
Regulatory Assets [Line Items]
Regulatory Assets	920	732
Regulatory Liabilities	406	345
Current regulatory assets	127	80
Noncurrent regulatory assets	793	652
PECO Energy Co | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	22	22
PECO Energy Co | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	11	17
PECO Energy Co | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	748	595
PECO Energy Co | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	1	15
PECO Energy Co | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	23	0
PECO Energy Co | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	15	13
PECO Energy Co | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
PECO Energy Co | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	9	16
PECO Energy Co | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	0	0
PECO Energy Co | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
PECO Energy Co | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	59	19
PECO Energy Co | Other
Regulatory Assets [Line Items]
Regulatory Assets	32	35
Baltimore Gas and Electric Company
Regulatory Assets [Line Items]
Regulatory Assets	956	704
Regulatory Liabilities	800	863
Current regulatory assets	229	177
Noncurrent regulatory assets	727	527
Baltimore Gas and Electric Company | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	49	69
Baltimore Gas and Electric Company | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	12	20
Baltimore Gas and Electric Company | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	23	21
Baltimore Gas and Electric Company | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	6	8
Baltimore Gas and Electric Company | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	84	55
Baltimore Gas and Electric Company | Deferred storm costs | MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets	27
Baltimore Gas and Electric Company | Deferred storm costs | 2028 | MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets	57
Baltimore Gas and Electric Company | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	25	25
Baltimore Gas and Electric Company | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	316	286
Baltimore Gas and Electric Company | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	14	12
Baltimore Gas and Electric Company | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	112
Baltimore Gas and Electric Company | Multi-year plan reconciliation | MARYLAND PUBLIC SERVICE COMMISSION [Domain]
Regulatory Assets [Line Items]
Regulatory Assets	52	60
Baltimore Gas and Electric Company | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	219	171
Baltimore Gas and Electric Company | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	5	0
Baltimore Gas and Electric Company | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	64	8
Baltimore Gas and Electric Company | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
Baltimore Gas and Electric Company | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Baltimore Gas and Electric Company | Other
Regulatory Assets [Line Items]
Regulatory Assets	27	29
Pepco Holdings LLC
Regulatory Assets [Line Items]
Regulatory Assets	1,924	2,065
Regulatory Liabilities	975	1,087
Current regulatory assets	337	455
Noncurrent regulatory assets	1,587	1,610
Pepco Holdings LLC | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	60	53
Pepco Holdings LLC | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	87	92
Pepco Holdings LLC | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	10	9
Pepco Holdings LLC | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	13	13
Pepco Holdings LLC | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	3	37
Pepco Holdings LLC | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	11	11
Pepco Holdings LLC | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	30	35
Pepco Holdings LLC | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	72	201
Pepco Holdings LLC | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	292	274
Pepco Holdings LLC | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	385	414
Pepco Holdings LLC | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	35	44
Pepco Holdings LLC | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
Pepco Holdings LLC | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	608	611
Pepco Holdings LLC | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	61	21
Pepco Holdings LLC | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	34	33
Pepco Holdings LLC | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	112	98
Pepco Holdings LLC | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
Pepco Holdings LLC | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Pepco Holdings LLC | Other
Regulatory Assets [Line Items]
Regulatory Assets	111	119
Potomac Electric Power Company
Regulatory Assets [Line Items]
Regulatory Assets	600	672
Regulatory Liabilities	397	461
Current regulatory assets	150	235
Noncurrent regulatory assets	450	437
Potomac Electric Power Company | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	18	25
Potomac Electric Power Company | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	41	53
Potomac Electric Power Company | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	6	6
Potomac Electric Power Company | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	10	10
Potomac Electric Power Company | COVID-19 Regulatory Asset | DISTRICT OF COLUMBIA
Regulatory Assets [Line Items]
Regulatory Assets	8
Potomac Electric Power Company | COVID-19 Regulatory Asset | MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets	2
Potomac Electric Power Company | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	3	37
Potomac Electric Power Company | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	11	11
Potomac Electric Power Company | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	9	2
Potomac Electric Power Company | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	11	41
Potomac Electric Power Company | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	187	187
Potomac Electric Power Company | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
Potomac Electric Power Company | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	137	144
Potomac Electric Power Company | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	15	3
Potomac Electric Power Company | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	100	98
Potomac Electric Power Company | Under-recovered revenue decoupling | 2024 | MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets	10
Potomac Electric Power Company | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
Potomac Electric Power Company | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Potomac Electric Power Company | Other
Regulatory Assets [Line Items]
Regulatory Assets	52	55
Delmarva Power & Light Company
Regulatory Assets [Line Items]
Regulatory Assets	272	282
Regulatory Liabilities	415	424
Current regulatory assets	54	80
Noncurrent regulatory assets	218	202
Delmarva Power & Light Company | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	17	22
Delmarva Power & Light Company | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	14	17
Delmarva Power & Light Company | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	2	2
Delmarva Power & Light Company | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	3	3
Delmarva Power & Light Company | COVID-19 Regulatory Asset | 2027 | MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets	1
Delmarva Power & Light Company | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	2	2
Delmarva Power & Light Company | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	2	26
Delmarva Power & Light Company | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	73	74
Delmarva Power & Light Company | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
Delmarva Power & Light Company | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	118	109
Delmarva Power & Light Company | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	22	5
Delmarva Power & Light Company | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
Delmarva Power & Light Company | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Delmarva Power & Light Company | Other
Regulatory Assets [Line Items]
Regulatory Assets	19	22
Atlantic City Electric Company
Regulatory Assets [Line Items]
Regulatory Assets	608	624
Regulatory Liabilities	146	182
Current regulatory assets	125	130
Noncurrent regulatory assets	483	494
Atlantic City Electric Company | Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	25	6
Atlantic City Electric Company | Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	32	22
Atlantic City Electric Company | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets	2	1
Atlantic City Electric Company | Carbon Mitigation Credit Rider
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets	19	31
Atlantic City Electric Company | Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets	59	134
Atlantic City Electric Company | Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets	32	13
Atlantic City Electric Company | Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Multi-year plan reconciliation
Regulatory Assets [Line Items]
Regulatory Assets	0
Atlantic City Electric Company | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Removal costs
Regulatory Assets [Line Items]
Regulatory Assets	354	359
Atlantic City Electric Company | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets	24	13
Atlantic City Electric Company | Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets	34	33
Atlantic City Electric Company | Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets	12	0
Atlantic City Electric Company | ZEC regulatory asset
Regulatory Assets [Line Items]
Regulatory Assets	0
Atlantic City Electric Company | Universal service fund charge under-recovery
Regulatory Assets [Line Items]
Regulatory Assets	0	0
Atlantic City Electric Company | Other
Regulatory Assets [Line Items]
Regulatory Assets	$ 15	$ 12