Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating revenues
Revenues from alternative revenue programs		$ (13)	$ (26)	$ (19)	$ (16)
Operating revenues from affiliates		0	0	0	0
Total operating revenues		7,689	8,076	17,166	17,769
Operating expenses
Operating and maintenance		2,159	2,307	4,347	4,691
Depreciation and amortization		1,079	1,088	2,154	2,179
Taxes other than income		418	428	863	874
Total operating expenses		6,881	7,138	15,142	15,786
Gain on sales of assets and businesses		33	4	36	60
Operating income		841	942	2,060	2,043
Other income and (deductions)
Interest expense, net		(403)	(367)	(800)	(732)
Interest expense to affiliates		(6)	(6)	(13)	(13)
Other, net		212	44	679	17
Total other income and (deductions)		(197)	(329)	(134)	(728)
Income before income taxes		644	613	1,926	1,315
Income taxes		144	66	454	125
Equity in losses of unconsolidated affiliates		(6)	(5)	(12)	(11)
Net income		494	542	1,460	1,179
Net income attributable to noncontrolling interests		10	3	69	54
Net income (loss) attributable to common shareholders		484	539	1,391	1,125
Other comprehensive (loss) income, net of income taxes
Prior service benefit reclassified to periodic benefit cost		(16)	(17)	(32)	(33)
Actuarial loss reclassified to periodic benefit cost		36	61	74	123
Pension and non-pension postretirement benefit plan valuation adjustment		0	(1)	(39)	18
Unrealized (loss) gain on cash flow hedges		0	4	0	12
Unrealized (loss) gain on investments in unconsolidated affiliates		(2)	2	(4)	3
Unrealized gain (loss) on foreign currency translation		3	(5)	4	(6)
Other comprehensive income		21	44	3	117
Comprehensive income		515	586	1,463	1,296
Comprehensive income attributable to noncontrolling interests		9	4	67	56
Comprehensive income attributable to common shareholders/membership interest		$ 506	$ 582	$ 1,396	$ 1,240
Average shares of common stock outstanding:
Basic average shares of common stock outstanding		972	967	972	967
Assumed exercise and/or distributions of stock-based awards		2	2	1	1
Diluted average shares of common stock outstanding	[1]	974	969	973	968
Earnings per average common share:
Basic earnings per average common share		$ 0.50	$ 0.56	$ 1.43	$ 1.16
Diluted earnings per average common share		$ 0.50	$ 0.56	$ 1.43	$ 1.16
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			2		5
Exelon Generation Co L L C [Member]
Operating revenues
Operating revenues from affiliates		$ 252	$ 273	$ 569	$ 671
Total operating revenues		4,210	4,579	9,506	10,090
Operating expenses
Purchased power and/or fuel from affiliates		3	3	4	7
Operating and maintenance		1,117	1,247	2,185	2,425
Operating and maintenance from affiliates		149	171	299	331
Depreciation and amortization		409	466	814	914
Taxes other than income		129	134	264	272
Total operating expenses		4,096	4,298	9,059	9,515
Gain on sales of assets and businesses		33	1	33	54
Operating income		147	282	480	629
Other income and (deductions)
Interest expense, net		(107)	(93)	(209)	(184)
Interest expense to affiliates		(9)	(9)	(18)	(18)
Other, net		171	29	601	(15)
Total other income and (deductions)		55	(73)	374	(217)
Income before income taxes		202	209	854	412
Income taxes		78	23	301	32
Equity in losses of unconsolidated affiliates		(6)	(5)	(13)	(12)
Net income		118	181	540	368
Net income attributable to noncontrolling interests		10	3	68	54
Net income attributable to membership interest		108	178	472	314
Other comprehensive (loss) income, net of income taxes
Unrealized (loss) gain on cash flow hedges		(1)	5	0	12
Unrealized (loss) gain on investments in unconsolidated affiliates		(2)	2	(4)	3
Unrealized gain (loss) on foreign currency translation		2	(5)	4	(6)
Other comprehensive income		(1)	2	0	9
Comprehensive income		117	183	540	377
Comprehensive income attributable to noncontrolling interests		9	4	66	56
Comprehensive income attributable to common shareholders/membership interest		108	179	474	321
Commonwealth Edison Co [Member]
Operating revenues
Revenues from alternative revenue programs		(14)	(17)	(42)	(12)
Operating revenues from affiliates		5	5	9	19
Total operating revenues		1,351	1,398	2,759	2,910
Operating expenses
Purchased power and/or fuel from affiliates		91	104	187	298
Operating and maintenance		245	255	504	509
Operating and maintenance from affiliates		60	69	122	129
Depreciation and amortization		257	231	508	459
Taxes other than income		71	79	148	156
Total operating expenses		1,040	1,111	2,174	2,335
Gain on sales of assets and businesses		0	1	3	5
Operating income		311	288	588	580
Other income and (deductions)
Interest expense, net		(86)	(82)	(171)	(168)
Interest expense to affiliates		(3)	(3)	(7)	(7)
Other, net		10	4	19	12
Total other income and (deductions)		(79)	(81)	(159)	(163)
Income before income taxes		232	207	429	417
Income taxes		46	43	85	88
Net income		186	164	344	329
Other comprehensive (loss) income, net of income taxes
Comprehensive income		186	164	344	329
PECO Energy Co [Member]
Operating revenues
Revenues from alternative revenue programs		(3)	2	(6)	1
Operating revenues from affiliates		2	2	3	3
Total operating revenues		655	653	1,554	1,518
Operating expenses
Purchased power and/or fuel from affiliates		35	24	79	60
Operating and maintenance		162	153	349	387
Operating and maintenance from affiliates		37	38	75	79
Depreciation and amortization		83	74	164	149
Taxes other than income		37	39	79	79
Total operating expenses		510	526	1,187	1,249
Operating income		145	127	367	269
Other income and (deductions)
Interest expense, net		(30)	(28)	(61)	(57)
Interest expense to affiliates		(3)	(4)	(6)	(7)
Other, net		3	0	7	2
Total other income and (deductions)		(30)	(32)	(60)	(62)
Income before income taxes		115	95	307	207
Income taxes		13	(1)	37	(3)
Net income		102	96	270	210
Other comprehensive (loss) income, net of income taxes
Comprehensive income		102	96	270	210
Baltimore Gas and Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		6	(4)	17	(17)
Operating revenues from affiliates		6	6	12	12
Total operating revenues		649	662	1,625	1,639
Operating expenses
Purchased power and/or fuel from affiliates		56	62	132	127
Operating and maintenance		142	135	294	318
Operating and maintenance from affiliates		40	41	78	79
Depreciation and amortization		117	114	252	248
Taxes other than income		62	59	131	124
Total operating expenses		569	578	1,325	1,378
Gain on sales of assets and businesses		0	1	0	1
Operating income		80	85	300	262
Other income and (deductions)
Interest expense, net		(29)	(25)	(58)	(51)
Other, net		5	4	11	9
Total other income and (deductions)		(24)	(21)	(47)	(42)
Income before income taxes		56	64	253	220
Income taxes		11	13	47	41
Net income		45	51	206	179
Other comprehensive (loss) income, net of income taxes
Comprehensive income		45	51	206	179
Pepco Holdings LLC [Member]
Operating revenues
Revenues from alternative revenue programs		(3)	(7)	12	12
Operating revenues from affiliates		3	3	7	7
Total operating revenues		1,091	1,076	2,319	2,327
Operating expenses
Purchased power and/or fuel from affiliates		70	81	171	186
Operating and maintenance		213	218	452	489
Operating and maintenance from affiliates		35	37	68	74
Depreciation and amortization		188	180	369	363
Taxes other than income		108	107	220	221
Total operating expenses		926	923	1,981	2,048
Operating income		165	153	338	279
Other income and (deductions)
Interest expense, net		(67)	(65)	(131)	(128)
Other, net		14	11	27	22
Total other income and (deductions)		(53)	(54)	(104)	(106)
Income before income taxes		112	99	234	173
Income taxes		6	15	11	24
Net income		106	84	223	149
Other comprehensive (loss) income, net of income taxes
Comprehensive income attributable to common shareholders/membership interest		106	84	223	149
Potomac Electric Power Company [Member]
Operating revenues
Revenues from alternative revenue programs		(1)	(10)	13	10
Operating revenues from affiliates		1	2	3	3
Total operating revenues		531	523	1,106	1,080
Operating expenses
Purchased power and/or fuel from affiliates		52	46	122	98
Operating and maintenance		59	60	123	133
Operating and maintenance from affiliates		52	56	107	113
Depreciation and amortization		93	92	186	188
Taxes other than income		90	90	182	183
Total operating expenses		438	438	929	939
Operating income		93	85	177	141
Other income and (deductions)
Interest expense, net		(34)	(32)	(68)	(63)
Other, net		7	8	14	16
Total other income and (deductions)		(27)	(24)	(54)	(47)
Income before income taxes		66	61	123	94
Income taxes		2	7	4	9
Net income		64	54	119	85
Other comprehensive (loss) income, net of income taxes
Comprehensive income		64	54	119	85
Delmarva Power and Light Company [Member]
Operating revenues
Revenues from alternative revenue programs		0	4	1	5
Operating revenues from affiliates		2	2	3	4
Total operating revenues		287	289	667	673
Operating expenses
Purchased power and/or fuel from affiliates		12	30	35	76
Operating and maintenance		39	36	84	94
Operating and maintenance from affiliates		38	41	76	81
Depreciation and amortization		45	43	91	88
Taxes other than income		14	13	28	28
Total operating expenses		243	247	550	582
Operating income		44	42	117	91
Other income and (deductions)
Interest expense, net		(15)	(14)	(30)	(27)
Other, net		5	3	7	5
Total other income and (deductions)		(10)	(11)	(23)	(22)
Income before income taxes		34	31	94	69
Income taxes		4	5	11	12
Net income		30	26	83	57
Other comprehensive (loss) income, net of income taxes
Comprehensive income		30	26	83	57
Atlantic City Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		(2)	(1)	(1)	(3)
Operating revenues from affiliates		1	1	1	2
Total operating revenues		274	265	547	575
Operating expenses
Purchased power and/or fuel from affiliates		6	6	13	12
Operating and maintenance		41	40	88	95
Operating and maintenance from affiliates		33	35	67	70
Depreciation and amortization		40	36	71	69
Taxes other than income		1	1	2	3
Total operating expenses		246	240	498	526
Operating income		28	25	49	49
Other income and (deductions)
Interest expense, net		(15)	(16)	(28)	(32)
Other, net		1	1	4	1
Total other income and (deductions)		(14)	(15)	(24)	(31)
Income before income taxes		14	10	25	18
Income taxes		0	2	1	3
Net income		14	8	24	15
Other comprehensive (loss) income, net of income taxes
Comprehensive income		14	8	24	15
Generation commodities and services
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		3,959	4,305	8,938	9,417
Operating expenses
Purchased power and/or fuel		2,289	2,277	5,493	5,566
Generation commodities and services | Exelon Generation Co L L C [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		3,958	4,306	8,937	9,419
Operating expenses
Purchased power and/or fuel		2,289	2,277	5,493	5,566
Rate-regulated utility revenues
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		3,743	3,797	8,247	8,368
Operating expenses
Purchased power and/or fuel		936	1,038	2,285	2,476
Electricity, US Regulated | Commonwealth Edison Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,360	1,410	2,792	2,903
Operating expenses
Purchased power and/or fuel		316	373	705	784
Electricity, US Regulated | PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		567	556	1,188	1,189
Operating expenses
Purchased power and/or fuel		124	161	275	361
Electricity, US Regulated | Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		540	542	1,191	1,196
Operating expenses
Purchased power and/or fuel		131	135	322	327
Electricity, US Regulated | Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,067	1,052	2,205	2,202
Operating expenses
Purchased power and/or fuel		303	288	658	662
Electricity, US Regulated | Potomac Electric Power Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		531	531	1,090	1,067
Operating expenses
Purchased power and/or fuel		92	94	209	224
Electricity, US Regulated | Delmarva Power and Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		261	255	568	558
Operating expenses
Purchased power and/or fuel		86	72	193	162
Electricity, US Regulated | Atlantic City Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		275	265	547	576
Operating expenses
Purchased power and/or fuel		125	122	257	277
Natural Gas, US Regulated | PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		89	93	369	325
Operating expenses
Purchased power and/or fuel		32	37	166	134
Natural Gas, US Regulated | Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		97	118	405	448
Operating expenses
Purchased power and/or fuel		21	32	116	155
Natural Gas, US Regulated | Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		24	28	95	106
Operating expenses
Purchased power and/or fuel		9	12	43	53
Natural Gas, US Regulated | Delmarva Power and Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		24	28	95	106
Operating expenses
Purchased power and/or fuel		$ 9	$ 12	$ 43	$ 53

[1] The number of stock options not included in the calculation of diluted common shares outstanding due to their antidilutive effect was immaterial for the three and six months ended June 30, 2019 and approximately 2 million and 5 million for the three and six months ended June 30, 2018, respectively.