Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 5,563	$ 5,327
Income (Loss) before income taxes	803	699
Income taxes	134	218
Net income (loss)	669	598
Capital expenditures	1,881	1,922
Assets	96,925		$ 95,349
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	669	481
Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	1,536	1,404
Revenue from Related Parties	3	3
Income (Loss) before income taxes	189	137
Income taxes	34	7
Net income (loss)	155	130
Capital expenditures	561	409
Assets	26,208		26,082
Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	5,563	5,327
Revenue from Related Parties	0	6
Depreciation and Amortization	860	817
Operating Expenses	4,457	4,427
Interest expense, net	412	338
Income (Loss) before income taxes	803	699
Income taxes	134	218
Capital expenditures	1,881	1,695
Assets	96,925		95,349
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	669	481
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(446)	(588)
Revenue from Related Parties	(445)	(587)
Depreciation and Amortization	0	0
Operating Expenses	(447)	(531)
Interest expense, net	0	0
Income (Loss) before income taxes	0	(43)
Income taxes	0	(10)
Capital expenditures	0	0
Assets	(4,194)		(4,260)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	(33)
Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	(103)	(97)
Revenue from Related Parties	(103)	(97)
Depreciation and Amortization	0	0
Operating Expenses	(103)	(97)
Interest expense, net	0	0
Income (Loss) before income taxes	0	0
Income taxes	0	0
Net income (loss)	0	0
Capital expenditures	0	0
Assets	(42)		(33)
Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,667	1,734
Depreciation and Amortization	338	321
Operating Expenses	1,256	1,406
Interest expense, net	117	100
Income (Loss) before income taxes	312	240
Income taxes	71	52
Capital expenditures	617	617
Assets	40,720		39,661
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	241	188
Commonwealth Edison Co [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	3	6
PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,112	1,047
Depreciation and Amortization	98	92
Operating Expenses	902	793
Interest expense, net	48	41
Income (Loss) before income taxes	170	220
Income taxes	4	14
Capital expenditures	335	344
Assets	14,738		14,502
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	166	206
PECO Energy Co [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	2	1
Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,257	1,154
Depreciation and Amortization	167	171
Operating Expenses	964	919
Interest expense, net	44	35
Income (Loss) before income taxes	252	207
Income taxes	52	9
Capital expenditures	350	303
Assets	13,411		13,350
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	200	198
Baltimore Gas and Electric Company [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	3	7
Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,536	1,404
Depreciation and Amortization	241	218
Operating Expenses	1,297	1,215
Interest expense, net	76	69
Income (Loss) before income taxes	189	137
Income taxes	34	7
Net income (loss)	155	130
Capital expenditures	561	409
Assets	26,208		26,082
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	155	130
Pepco Holdings LLC [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	3	3
Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	710	614
Depreciation and Amortization	108	108
Operating Expenses	610	547
Interest expense, net	39	36
Income (Loss) before income taxes	77	44
Income taxes	12	(2)
Net income (loss)	65	46
Capital expenditures	264	218
Assets	10,795		10,657
Potomac Electric Power Company [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	1
Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	474	431
Depreciation and Amortization	60	57
Operating Expenses	388	357
Interest expense, net	17	16
Income (Loss) before income taxes	72	60
Income taxes	12	4
Net income (loss)	60	56
Capital expenditures	134	103
Assets	5,804		5,802
Delmarva Power and Light Company [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	2	1
Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	353	349
Depreciation and Amortization	67	47
Operating Expenses	298	311
Interest expense, net	16	14
Income (Loss) before income taxes	44	27
Income taxes	11	1
Net income (loss)	33	26
Capital expenditures	161	87
Assets	5,013		4,979
Atlantic City Electric Company [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	1
Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenues	437	576
Depreciation and Amortization	16	15
Operating Expenses	485	625
Interest expense, net	127	93
Income (Loss) before income taxes	(120)	(62)
Income taxes	(27)	146
Capital expenditures	18	22
Assets	6,042		6,014
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(93)	(208)
Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	102	107
Depreciation and Amortization	6	6
Operating Expenses	104	97
Interest expense, net	4	3
Income (Loss) before income taxes	(4)	6
Income taxes	(1)	4
Net income (loss)	(3)	2
Capital expenditures	2	1
Assets	4,638		$ 4,677
Corporate and Other [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	434	576
Corporate and Other [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	102	97
Rate-regulated electric revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,462	4,481
Rate-regulated electric revenues [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,371	1,323
Rate-regulated electric revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,707	4,522
Rate-regulated electric revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(5)	(7)
Rate-regulated electric revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(4)	7
Rate-regulated electric revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,667	1,734
Rate-regulated electric revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	795	741
Rate-regulated electric revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	814	736
Rate-regulated electric revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,436	1,318
Rate-regulated electric revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	710	614
Rate-regulated electric revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	377	348
Rate-regulated electric revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	353	349
Rate-regulated electric revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated electric revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	822	817
Rate-regulated natural gas revenues [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	97	83
Rate-regulated natural gas revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	856	805
Rate-regulated natural gas revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(1)	(2)
Rate-regulated natural gas revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	317	306
Rate-regulated natural gas revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	443	418
Rate-regulated natural gas revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	97	83
Rate-regulated natural gas revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	97	83
Rate-regulated natural gas revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(440)	(579)
Shared service and other revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(99)	(104)
Shared service and other revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	3
Shared service and other revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	437	576
Shared service and other revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 102	$ 107