Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents		$ 880	$ 1,349
Restricted cash and cash equivalents		223	247
Accounts receivable, net
Customer		4,564	4,607
Other		1,062	1,256
Mark-to-market derivative assets, current		652	804
Unamortized energy contract assets, current		49	48
Inventories, net
Fossil fuel and emission allowances		179	334
Materials and supplies		1,380	1,351
Regulatory assets, current		1,191	1,222
Assets held for sale		890	904
Other		1,406	1,238
Total current assets		12,476	13,360
Property, plant and equipment, net		77,460	76,707
Deferred debits and other assets
Regulatory assets, noncurrent		8,222	8,237
Nuclear decommissioning trust funds		12,302	11,661
Investments		620	625
Goodwill		6,677	6,677
Mark-to-market derivative assets, noncurrent		454	452
Unamortized energy contract assets, noncurrent		365	372
Other		3,017	1,575
Total deferred debits and other assets		31,657	29,599
Total assets	[1]	121,593	119,666
Current Liabilities
Short-term borrowings		1,254	714
Long-term debt due within one year		2,508	1,349
Accounts payable		3,327	3,800
Accrued expenses		1,725	2,112
Payable to affiliates, current		5	5
Regulatory liabilities, current		522	644
Mark-to-market derivative liabilities, current		345	475
Unamortized energy contract liabilities, current		151	149
Renewable energy credit obligation		348	344
Liabilities held for sale		799	777
Other		1,245	1,035
Total current liabilities		12,229	11,404
Long-term debt		32,960	34,075
Long-term debt to financing trusts		390	390
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		11,642	11,330
Asset retirement obligations, noncurrent		9,967	9,679
Pension obligations		3,734	3,988
Non-pension postretirement benefit obligations		1,984	1,928
Spent nuclear fuel obligation		1,178	1,171
Regulatory liabilities, noncurrent		9,781	9,559
Mark-to-market derivative liabilities, noncurrent		434	479
Unamortized energy contract liabilities, noncurrent		432	463
Other		3,158	2,130
Total deferred credits and other liabilities		42,310	40,727
Total liabilities	[1]	87,889	86,596
Commitments and contingencies
Shareholders' equity
Common stock		19,171	19,116
Treasury stock, at cost (2 shares at March 31, 2019 and December 31, 2018)		(123)	(123)
Retained earnings		15,321	14,766
Accumulated other comprehensive loss, net		(3,012)	(2,995)
Total shareholders’ equity		31,357	30,764
Member’s equity
Noncontrolling Interests		2,347	2,306
Total equity		33,704	33,070
Total liabilities and shareholders’ equity		121,593	119,666
Variable Interest Entity, Consolidated, Assets, Pledged		9,546	9,667
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,572	3,548
Exelon Generation Co L L C [Member]
Current Assets
Cash and cash equivalents		537	750
Restricted cash and cash equivalents		139	153
Accounts receivable, net
Customer		2,800	2,941
Other		367	562
Mark-to-market derivative assets, current		652	804
Receivable from affiliates, current		163	173
Unamortized energy contract assets, current		49	49
Inventories, net
Fossil fuel and emission allowances		146	251
Materials and supplies		965	963
Assets held for sale		890	904
Other		1,013	883
Total current assets		7,721	8,433
Property, plant and equipment, net		24,034	23,981
Deferred debits and other assets
Nuclear decommissioning trust funds		12,302	11,661
Investments		404	414
Goodwill		47	47
Mark-to-market derivative assets, noncurrent		454	452
Prepaid pension asset		1,525	1,421
Unamortized energy contract assets, noncurrent		364	371
Deferred income taxes		18	21
Other		1,813	755
Total deferred debits and other assets		16,927	15,142
Total assets	[2]	48,682	47,556
Current Liabilities
Long-term debt due within one year		2,365	906
Accounts payable		1,566	1,847
Accrued expenses		675	898
Payable to affiliates, current		136	139
Borrowings from Exelon intercompany money pool		0	100
Mark-to-market derivative liabilities, current		318	449
Unamortized energy contract liabilities, current		28	31
Renewable energy credit obligation		348	343
Liabilities held for sale		799	777
Other		425	279
Total current liabilities		6,660	5,769
Long-term debt		5,487	6,989
Long-term debt to affiliates		895	898
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,502	3,383
Asset retirement obligations, noncurrent		9,737	9,450
Non-pension postretirement benefit obligations		894	900
Spent nuclear fuel obligation		1,178	1,171
Payables to affiliates, noncurrent		2,870	2,606
Mark-to-market derivative liabilities, noncurrent		219	252
Unamortized energy contract liabilities, noncurrent		16	20
Other		1,528	610
Total deferred credits and other liabilities		19,944	18,392
Total liabilities	[2]	32,986	32,048
Commitments and contingencies
Shareholders' equity
Retained earnings		3,862	3,724
Accumulated other comprehensive loss, net		(36)	(38)
Member’s equity
Membership interest		9,525	9,518
Total members' equity		13,351	13,204
Noncontrolling Interests		2,345	2,304
Total equity		15,696	15,508
Total liabilities and shareholders’ equity		48,682	47,556
Variable Interest Entity, Consolidated, Assets, Pledged		9,515	9,634
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,508	3,480
Commonwealth Edison Co [Member]
Current Assets
Cash and cash equivalents		68	135
Restricted cash and cash equivalents		17	29
Accounts receivable, net
Customer		539	539
Other		336	320
Receivable from affiliates, current		21	20
Inventories, net
Inventories, net		152	148
Regulatory assets, current		285	293
Other		89	86
Total current assets		1,507	1,570
Property, plant and equipment, net		22,274	22,058
Deferred debits and other assets
Regulatory assets, noncurrent		1,338	1,307
Investments		6	6
Goodwill		2,625	2,625
Receivable from affiliates, noncurrent		2,412	2,217
Prepaid pension asset		1,073	1,035
Other		347	395
Total deferred debits and other assets		7,801	7,585
Total assets		31,582	31,213
Current Liabilities
Short-term borrowings		322	0
Long-term debt due within one year		0	300
Accounts payable		491	607
Accrued expenses		229	373
Payable to affiliates, current		74	119
Customer deposits		112	111
Regulatory liabilities, current		241	293
Mark-to-market derivative liabilities, current		27	26
Other		98	96
Total current liabilities		1,594	1,925
Long-term debt		8,194	7,801
Long-term debt to financing trusts		205	205
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,870	3,813
Asset retirement obligations, noncurrent		119	118
Non-pension postretirement benefit obligations		196	201
Regulatory liabilities, noncurrent		6,269	6,050
Mark-to-market derivative liabilities, noncurrent		213	223
Other		582	630
Total deferred credits and other liabilities		11,249	11,035
Total liabilities		21,242	20,966
Commitments and contingencies
Shareholders' equity
Common stock		1,588	1,588
Other paid-in capital		7,385	7,322
Retained deficit unappropriated		(1,639)	(1,639)
Retained earnings appropriated		3,006	2,976
Total shareholders’ equity		10,340	10,247
Member’s equity
Total liabilities and shareholders’ equity		31,582	31,213
PECO Energy Co [Member]
Current Assets
Cash and cash equivalents		41	130
Restricted cash and cash equivalents		6	5
Accounts receivable, net
Customer		394	321
Other		148	151
Inventories, net
Fossil fuel and emission allowances		15	38
Materials and supplies		37	37
Prepaid utility taxes		100	0
Regulatory assets, current		54	81
Other		21	19
Total current assets		816	782
Property, plant and equipment, net		8,766	8,610
Deferred debits and other assets
Regulatory assets, noncurrent		491	460
Investments		25	25
Receivable from affiliates, noncurrent		457	389
Prepaid pension asset		372	349
Other		29	27
Total deferred debits and other assets		1,374	1,250
Total assets		10,956	10,642
Current Liabilities
Accounts payable		379	370
Accrued expenses		119	113
Payable to affiliates, current		66	59
Customer deposits		68	68
Regulatory liabilities, current		123	175
Other		32	24
Total current liabilities		787	809
Long-term debt		3,084	3,084
Long-term debt to financing trusts		184	184
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,974	1,933
Asset retirement obligations, noncurrent		27	27
Non-pension postretirement benefit obligations		288	288
Regulatory liabilities, noncurrent		488	421
Other		81	76
Total deferred credits and other liabilities		2,858	2,745
Total liabilities		6,913	6,822
Commitments and contingencies
Shareholders' equity
Common stock		2,723	2,578
Retained earnings		1,320	1,242
Total shareholders’ equity		4,043	3,820
Member’s equity
Total liabilities and shareholders’ equity		10,956	10,642
Baltimore Gas and Electric Company [Member]
Current Assets
Cash and cash equivalents		12	7
Restricted cash and cash equivalents		4	6
Accounts receivable, net
Customer		385	353
Other		89	90
Receivable from affiliates, current		0	1
Inventories, net
Fossil fuel and emission allowances		16	36
Materials and supplies		42	39
Prepaid utility taxes		38	74
Regulatory assets, current		161	177
Other		6	3
Total current assets		753	786
Property, plant and equipment, net		8,408	8,243
Deferred debits and other assets
Regulatory assets, noncurrent		395	398
Investments		5	5
Prepaid pension asset		301	279
Other		105	5
Total deferred debits and other assets		806	687
Total assets		9,967	9,716
Current Liabilities
Short-term borrowings		106	35
Accounts payable		291	295
Accrued expenses		142	155
Payable to affiliates, current		54	65
Customer deposits		120	120
Regulatory liabilities, current		67	77
Other		54	27
Total current liabilities		834	774
Long-term debt		2,876	2,876
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,275	1,222
Asset retirement obligations, noncurrent		24	24
Non-pension postretirement benefit obligations		198	201
Regulatory liabilities, noncurrent		1,172	1,192
Other		130	73
Total deferred credits and other liabilities		2,799	2,712
Total liabilities		6,509	6,362
Commitments and contingencies
Shareholders' equity
Common stock		1,714	1,714
Retained earnings		1,744	1,640
Total shareholders’ equity		3,458	3,354
Member’s equity
Total liabilities and shareholders’ equity		9,967	9,716
Pepco Holdings LLC [Member]
Current Assets
Cash and cash equivalents		33	124
Restricted cash and cash equivalents		39	43
Accounts receivable, net
Customer		445	453
Other		189	177
Receivable from affiliates, current		1	0
Inventories, net
Fossil fuel and emission allowances		2	9
Materials and supplies		184	163
Regulatory assets, current		506	489
Other		54	75
Total current assets		1,453	1,533
Property, plant and equipment, net		13,619	13,446
Deferred debits and other assets
Regulatory assets, noncurrent		2,236	2,312
Investments		132	130
Goodwill		4,005	4,005
Prepaid pension asset		467	486
Deferred income taxes		12	12
Other		370	60
Total deferred debits and other assets		7,222	7,005
Total assets	[3]	22,294	21,984
Current Liabilities
Short-term borrowings		326	179
Long-term debt due within one year		125	125
Accounts payable		441	496
Accrued expenses		253	256
Payable to affiliates, current		87	94
Customer deposits		117	116
Regulatory liabilities, current		76	84
Unamortized energy contract liabilities, current		123	119
Other		127	123
Total current liabilities		1,675	1,592
Long-term debt		6,119	6,134
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		2,182	2,146
Asset retirement obligations, noncurrent		52	52
Non-pension postretirement benefit obligations		101	103
Regulatory liabilities, noncurrent		1,829	1,864
Unamortized energy contract liabilities, noncurrent		416	442
Other		630	369
Total deferred credits and other liabilities		5,210	4,976
Total liabilities	[3]	13,004	12,702
Commitments and contingencies
Shareholders' equity
Retained earnings		51	62
Member’s equity
Membership interest		9,239	9,220
Total members' equity		9,290	9,282
Total equity		9,290	9,282
Total liabilities and shareholders’ equity		22,294	21,984
Variable Interest Entity, Consolidated, Assets, Pledged		31	33
Variable Interest Entity, Consolidated, Liabilities, No Recourse		64	69
Potomac Electric Power Company [Member]
Current Assets
Cash and cash equivalents		11	16
Restricted cash and cash equivalents		35	37
Accounts receivable, net
Customer		219	225
Other		102	81
Receivable from affiliates, current		1	1
Inventories, net
Inventories, net		109	93
Regulatory assets, current		270	270
Other		22	37
Total current assets		769	760
Property, plant and equipment, net		6,534	6,460
Deferred debits and other assets
Regulatory assets, noncurrent		620	643
Investments		106	105
Prepaid pension asset		311	316
Other		80	15
Total deferred debits and other assets		1,117	1,079
Total assets		8,420	8,299
Current Liabilities
Short-term borrowings		105	40
Long-term debt due within one year		15	15
Accounts payable		188	214
Accrued expenses		139	126
Payable to affiliates, current		65	62
Customer deposits		55	54
Regulatory liabilities, current		6	7
Merger related obligation		38	38
Current portion of DC PLUG obligation		30	30
Other		17	42
Total current liabilities		658	628
Long-term debt		2,705	2,704
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,081	1,064
Non-pension postretirement benefit obligations		26	29
Regulatory liabilities, noncurrent		805	822
Other		360	312
Total deferred credits and other liabilities		2,272	2,227
Total liabilities		5,635	5,559
Commitments and contingencies
Shareholders' equity
Common stock		1,650	1,636
Retained earnings		1,135	1,104
Total shareholders’ equity		2,785	2,740
Member’s equity
Total liabilities and shareholders’ equity		8,420	8,299
Delmarva Power and Light Company [Member]
Current Assets
Cash and cash equivalents		7	23
Restricted cash and cash equivalents		1	1
Accounts receivable, net
Customer		141	134
Other		39	46
Receivable from affiliates, current		2	0
Inventories, net
Fossil fuel and emission allowances		2	9
Materials and supplies		43	37
Regulatory assets, current		60	59
Other		21	27
Total current assets		316	336
Property, plant and equipment, net		3,848	3,821
Deferred debits and other assets
Regulatory assets, noncurrent		225	231
Goodwill		8	8
Prepaid pension asset		182	186
Other		81	6
Total deferred debits and other assets		496	431
Total assets		4,660	4,588
Current Liabilities
Short-term borrowings		5	0
Long-term debt due within one year		91	91
Accounts payable		98	111
Accrued expenses		50	39
Payable to affiliates, current		21	33
Customer deposits		36	35
Regulatory liabilities, current		49	59
Other		16	7
Total current liabilities		366	375
Long-term debt		1,404	1,403
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		643	628
Non-pension postretirement benefit obligations		16	17
Regulatory liabilities, noncurrent		596	606
Other		114	50
Total deferred credits and other liabilities		1,369	1,301
Total liabilities		3,139	3,079
Commitments and contingencies
Shareholders' equity
Common stock		914	914
Retained earnings		607	595
Total shareholders’ equity		1,521	1,509
Member’s equity
Total liabilities and shareholders’ equity		4,660	4,588
Atlantic City Electric Company [Member]
Current Assets
Cash and cash equivalents		6	7
Restricted cash and cash equivalents		3	4
Accounts receivable, net
Customer		85	95
Other		52	55
Receivable from affiliates, current		1	1
Inventories, net
Inventories, net		32	33
Regulatory assets, current		53	40
Other		6	5
Total current assets		238	240
Property, plant and equipment, net		3,041	2,966
Deferred debits and other assets
Regulatory assets, noncurrent		377	386
Prepaid pension asset		63	67
Other		64	40
Total deferred debits and other assets		504	493
Total assets	[4]	3,783	3,699
Current Liabilities
Short-term borrowings		216	139
Long-term debt due within one year		19	18
Accounts payable		139	154
Accrued expenses		38	35
Payable to affiliates, current		24	28
Customer deposits		26	26
Regulatory liabilities, current		20	18
Other		10	4
Total current liabilities		492	422
Long-term debt		1,165	1,170
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		539	535
Non-pension postretirement benefit obligations		17	17
Regulatory liabilities, noncurrent		395	402
Other		46	27
Total deferred credits and other liabilities		997	981
Total liabilities	[4]	2,654	2,573
Commitments and contingencies
Shareholders' equity
Common stock		984	979
Retained earnings		145	147
Total shareholders’ equity		1,129	1,126
Member’s equity
Total liabilities and shareholders’ equity		3,783	3,699
Variable Interest Entity, Consolidated, Assets, Pledged		22	23
Variable Interest Entity, Consolidated, Liabilities, No Recourse		$ 54	$ 59

[1] Exelon’s consolidated assets include $9,546 million and $9,667 million at March 31, 2019 and December 31, 2018, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $3,572 million and $3,548 million at March 31, 2019 and December 31, 2018, respectively, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 2 — Variable Interest Entities for additional information.

[2] Generation’s consolidated assets include $9,515 million and $9,634 million at March 31, 2019 and December 31, 2018, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Generation’s consolidated liabilities include $3,508 million and $3,480 million at March 31, 2019 and December 31, 2018, respectively, of certain VIEs for which the VIE creditors do not have recourse to Generation. See Note 2 — Variable Interest Entities for additional information.

[3] PHI’s consolidated total assets include $31 million and $33 million at March 31, 2019 and December 31, 2018, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $64 million and $69 million at March 31, 2019 and December 31, 2018, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 2 — Variable Interest Entities for additional information.

[4] ACE’s consolidated total assets include $22 million and $23 million at March 31, 2019 and December 31, 2018, respectively, of ACE's consolidated VIE that can only be used to settle the liabilities of the VIE. ACE’s consolidated total liabilities include $54 million and $59 million at March 31, 2019 and December 31, 2018, respectively, of ACE's consolidated VIE for which the VIE creditors do not have recourse to ACE. See Note 2 — Variable Interest Entities for additional information.