Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents		$ 694	$ 898
Restricted cash and cash equivalents		206	207
Accounts receivable, net
Customer		4,094	4,445
Other		1,407	1,132
Mark-to-market derivative assets, current		799	976
Unamortized energy contract assets, current		46	60
Inventories, net
Energy Related Inventory, Other Fossil Fuel		270	340
Materials and Supplies		1,320	1,311
Regulatory Assets, Current		1,293	1,267
Other		1,360	1,260
Total current assets		11,489	11,896
Property, plant and equipment, net		75,284	74,202
Deferred debits and other assets
Regulatory Assets, Noncurrent		8,023	8,021
Nuclear decommissioning trust funds		13,110	13,272
Investments		636	640
Goodwill		6,677	6,677
Mark-to-market derivative assets, noncurrent		457	337
Unamortized energy contract assets, noncurrent		379	395
Other		1,194	1,330
Total deferred debits and other assets		30,476	30,672
Total assets	[1]	117,249	116,770
Current Liabilities
Short-term borrowings		1,252	929
Long-term debt due within one year		1,158	2,088
Accounts payable		3,113	3,532
Accrued expenses		1,665	1,837
Payable to affiliates, current		5	5
Regulatory Liability, Current		701	523
Mark-to-market derivative liabilities, current		268	232
Unamortized energy contract liabilities, current		171	231
Renewable energy credit obligation		257	352
PHI merger related obligation		63	87
Other		973	982
Total current liabilities		9,626	10,798
Long-term debt		33,179	32,176
Long-term debt to financing trust		389	389
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		11,484	11,235
Asset Retirement Obligations, Noncurrent		10,222	10,029
Pension obligations		3,412	3,736
Non-pension postretirement benefit obligations		2,132	2,093
Spent nuclear fuel obligation		1,157	1,147
Regulatory Liability, Noncurrent		9,677	9,865
Mark-to-market derivative liabilities, noncurrent		507	409
Unamortized energy contract liabilities, noncurrent		538	609
Other		2,087	2,097
Total deferred credits and other liabilities		41,216	41,220
Total liabilities	[1]	84,410	84,583
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		19,008	18,964
Treasury stock, at cost (2 shares at June 30, 2018 and December 31, 2017)		(123)	(123)
Retained Earnings		14,551	14,081
Accumulated other comprehensive loss, net		(2,921)	(3,026)
Total shareholders’ equity		30,515	29,896
Member’s equity
Noncontrolling Interests		2,324	2,291
Total equity		32,839	32,187
Total liabilities and shareholders’ equity		117,249	116,770
Variable Interest Entity, Consolidated, Assets, Not Pledged		9,612	9,597
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,544	3,618
Exelon Generation Co L L C [Member]
Current Assets
Cash and cash equivalents		420	416
Restricted cash and cash equivalents		130	138
Accounts receivable, net
Customer		2,435	2,697
Other		276	321
Mark-to-market derivative assets, current		799	976
Receivable from affiliates, current		146	140
Unamortized energy contract assets, current		46	60
Inventories, net
Energy Related Inventory, Other Fossil Fuel		214	264
Materials and Supplies		953	937
Other		1,148	933
Total current assets		6,567	6,882
Property, plant and equipment, net		24,479	24,906
Deferred debits and other assets
Nuclear decommissioning trust funds		13,110	13,272
Investments		423	433
Goodwill		47	47
Mark-to-market derivative assets, noncurrent		457	334
Prepaid pension asset		1,522	1,502
Unamortized energy contract assets, noncurrent		378	395
Deferred income taxes		6	16
Other		679	670
Total deferred debits and other assets		16,622	16,669
Total assets	[2]	47,668	48,457
Current Liabilities
Short-term borrowings		0	2
Long-term debt due within one year		321	346
Accounts payable		1,264	1,773
Accrued expenses		976	1,022
Payable to affiliates, current		128	123
Borrowings from Exelon intercompany money pool		0	54
Mark-to-market derivative liabilities, current		245	211
Unamortized energy contract liabilities, current		36	43
Renewable energy credit obligation		257	352
Other		295	265
Total current liabilities		3,522	4,191
Long-term debt		7,661	7,734
Long-term debt to affiliate		904	910
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,673	3,811
Asset Retirement Obligations, Noncurrent		10,037	9,844
Non-pension postretirement benefit obligations		907	916
Spent nuclear fuel obligation		1,157	1,147
Payables to affiliates, noncurrent		2,916	3,065
Mark-to-market derivative liabilities, noncurrent		270	174
Unamortized energy contract liabilities, noncurrent		34	48
Other		648	658
Total deferred credits and other liabilities		19,642	19,663
Total liabilities	[2]	31,729	32,498
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Retained Earnings		4,292	4,349
Accumulated other comprehensive loss, net		(33)	(37)
Member’s equity
Membership Interest		9,357	9,357
Total members' equity		13,616	13,669
Noncontrolling Interests		2,323	2,290
Total equity		15,939	15,959
Total liabilities and shareholders’ equity		47,668	48,457
Variable Interest Entity, Consolidated, Assets, Not Pledged		9,575	9,556
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,456	3,516
Commonwealth Edison Co [Member]
Current Assets
Cash and cash equivalents		30	76
Restricted cash and cash equivalents		5	5
Accounts receivable, net
Customer		579	559
Other		376	266
Receivable from affiliates, current		21	13
Inventories, net
Inventories, net		146	152
Regulatory Assets, Current		237	225
Other		86	68
Total current assets		1,480	1,364
Property, plant and equipment, net		21,323	20,723
Deferred debits and other assets
Regulatory Assets, Noncurrent		1,134	1,054
Investments		6	6
Goodwill		2,625	2,625
Receivable from affiliate, noncurrent		2,430	2,528
Prepaid pension asset		1,130	1,188
Other		318	238
Total deferred debits and other assets		7,643	7,639
Total assets		30,446	29,726
Current Liabilities
Short-term borrowings		320	0
Long-term debt due within one year		440	840
Accounts payable		547	568
Accrued expenses		285	327
Payable to affiliates, current		97	74
Regulatory Liability, Current		287	249
Mark-to-market derivative liabilities, current		23	21
Customer deposits		111	112
Other		81	103
Total current liabilities		2,191	2,294
Long-term debt		7,255	6,761
Long-term debt to financing trust		205	205
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,597	3,469
Asset Retirement Obligations, Noncurrent		111	111
Non-pension postretirement benefit obligations		210	219
Regulatory Liability, Noncurrent		6,221	6,328
Mark-to-market derivative liabilities, noncurrent		229	235
Other		560	562
Total deferred credits and other liabilities		10,928	10,924
Total liabilities		20,579	20,184
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,588	1,588
Other paid-in capital		7,047	6,822
Retained Earnings, Unappropriated		(1,639)	(1,639)
Retained Earnings, Appropriated		2,871	2,771
Total shareholders’ equity		9,867	9,542
Member’s equity
Total liabilities and shareholders’ equity		30,446	29,726
PECO Energy Co [Member]
Current Assets
Cash and cash equivalents		18	271
Restricted cash and cash equivalents		5	4
Accounts receivable, net
Customer		285	327
Other		178	105
Receivable from affiliates, current		0	0
Inventories, net
Energy Related Inventory, Other Fossil Fuel		24	31
Materials and Supplies		33	30
Regulatory Assets, Current		75	29
Prepaid Taxes		72	8
Other		25	17
Total current assets		715	822
Property, plant and equipment, net		8,307	8,053
Deferred debits and other assets
Regulatory Assets, Noncurrent		427	381
Investments		25	25
Receivable from affiliate, noncurrent		485	537
Prepaid pension asset		355	340
Other		31	12
Total deferred debits and other assets		1,323	1,295
Total assets		10,345	10,170
Current Liabilities
Short-term borrowings		50	0
Long-term debt due within one year		0	500
Accounts payable		349	370
Accrued expenses		118	114
Payable to affiliates, current		48	53
Borrowings from Exelon intercompany money pool		233	0
Regulatory Liability, Current		168	141
Customer deposits		67	66
Other		32	23
Total current liabilities		1,065	1,267
Long-term debt		2,773	2,403
Long-term debt to financing trust		184	184
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,854	1,789
Asset Retirement Obligations, Noncurrent		27	27
Non-pension postretirement benefit obligations		288	288
Regulatory Liability, Noncurrent		545	549
Other		74	86
Total deferred credits and other liabilities		2,788	2,739
Total liabilities		6,810	6,593
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		2,530	2,489
Retained Earnings		1,005	1,087
Accumulated other comprehensive loss, net		0	1
Total shareholders’ equity		3,535	3,577
Member’s equity
Total liabilities and shareholders’ equity		10,345	10,170
Baltimore Gas and Electric Company [Member]
Current Assets
Cash and cash equivalents		7	17
Restricted cash and cash equivalents		1	1
Accounts receivable, net
Customer		300	375
Other		89	94
Receivable from affiliates, current		0	1
Inventories, net
Materials and Supplies		45	40
Energy Related Inventory, Natural Gas in Storage		27	37
Regulatory Assets, Current		185	174
Prepaid Taxes		0	69
Other		4	3
Total current assets		658	811
Property, plant and equipment, net		7,864	7,602
Deferred debits and other assets
Regulatory Assets, Noncurrent		405	397
Investments		6	5
Prepaid pension asset		302	285
Other		6	4
Total deferred debits and other assets		719	691
Total assets		9,241	9,104
Current Liabilities
Short-term borrowings		136	77
Accounts payable		249	265
Accrued expenses		95	164
Payable to affiliates, current		48	52
Regulatory Liability, Current		106	62
Customer deposits		120	116
Other		23	24
Total current liabilities		777	760
Long-term debt		2,578	2,577
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,306	1,244
Asset Retirement Obligations, Noncurrent		23	23
Non-pension postretirement benefit obligations		199	202
Regulatory Liability, Noncurrent		1,070	1,101
Other		73	56
Total deferred credits and other liabilities		2,671	2,626
Total liabilities		6,026	5,963
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,605	1,605
Retained Earnings		1,610	1,536
Total shareholders’ equity		3,215	3,141
Member’s equity
Total liabilities and shareholders’ equity		9,241	9,104
Pepco Holdings LLC [Member]
Current Assets
Cash and cash equivalents		195	30
Restricted cash and cash equivalents		38	42
Accounts receivable, net
Customer		495	486
Other		201	206
Inventories, net
Materials and Supplies		145	151
Energy Related Inventory, Natural Gas in Storage		5	7
Regulatory Assets, Current		512	554
Other		81	75
Total current assets		1,672	1,551
Property, plant and equipment, net		12,929	12,498
Deferred debits and other assets
Regulatory Assets, Noncurrent		2,439	2,493
Investments		133	132
Long-term note receivable		0	4
Goodwill		4,005	4,005
Prepaid pension asset		513	490
Deferred income taxes		5	4
Other		70	70
Total deferred debits and other assets		7,165	7,198
Total assets	[3]	21,766	21,247
Current Liabilities
Short-term borrowings		247	350
Long-term debt due within one year		379	396
Accounts payable		514	348
Accrued expenses		220	261
Payable to affiliates, current		94	90
Borrowings from Exelon intercompany money pool		7	0
Regulatory Liability, Current		125	56
Unamortized energy contract liabilities, current		134	188
Customer deposits		111	119
Merger related obligation		38	42
Other		57	81
Total current liabilities		1,926	1,931
Long-term debt		5,737	5,478
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		2,146	2,070
Asset Retirement Obligations, Noncurrent		16	16
Non-pension postretirement benefit obligations		100	105
Regulatory Liability, Noncurrent		1,834	1,872
Unamortized energy contract liabilities, noncurrent		504	561
Other		403	389
Total deferred credits and other liabilities		5,003	5,013
Total liabilities	[3]	12,666	12,422
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Retained Earnings		30	(10)
Member’s equity
Membership Interest		9,070	8,835
Total members' equity		9,100	8,825
Total equity		9,100	8,825
Total liabilities and shareholders’ equity		21,766	21,247
Variable Interest Entity, Consolidated, Assets, Not Pledged			41
Variable Interest Entity, Consolidated, Liabilities, No Recourse			102
Potomac Electric Power Company [Member]
Current Assets
Cash and cash equivalents		47	5
Restricted cash and cash equivalents		33	35
Accounts receivable, net
Customer		272	250
Other		91	87
Inventories, net
Inventories, net		85	87
Regulatory Assets, Current		248	213
Other		11	33
Total current assets		787	710
Property, plant and equipment, net		6,207	6,001
Deferred debits and other assets
Regulatory Assets, Noncurrent		682	678
Investments		105	102
Prepaid pension asset		321	322
Other		21	19
Total deferred debits and other assets		1,129	1,121
Total assets		8,123	7,832
Current Liabilities
Short-term borrowings		0	26
Long-term debt due within one year		20	19
Accounts payable		245	139
Accrued expenses		137	137
Payable to affiliates, current		63	74
Regulatory Liability, Current		30	3
Customer deposits		51	54
Merger related obligation		38	42
Current portion of DC PLUG obligation		30	28
Other		10	28
Total current liabilities		624	550
Long-term debt		2,611	2,521
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,101	1,063
Non-pension postretirement benefit obligations		32	36
Regulatory Liability, Noncurrent		791	829
Other		311	300
Total deferred credits and other liabilities		2,235	2,228
Total liabilities		5,470	5,299
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,555	1,470
Retained Earnings		1,098	1,063
Total shareholders’ equity		2,653	2,533
Member’s equity
Total liabilities and shareholders’ equity		8,123	7,832
Delmarva Power and Light Company [Member]
Current Assets
Cash and cash equivalents		141	2
Restricted cash and cash equivalents		0	0
Accounts receivable, net
Customer		119	146
Other		43	38
Receivable from affiliates, current		1	0
Inventories, net
Materials and Supplies		34	36
Energy Related Inventory, Natural Gas in Storage		5	7
Regulatory Assets, Current		64	69
Other		18	27
Total current assets		425	325
Property, plant and equipment, net		3,689	3,579
Deferred debits and other assets
Regulatory Assets, Noncurrent		242	245
Goodwill		8	8
Prepaid pension asset		189	193
Other		9	7
Total deferred debits and other assets		448	453
Total assets		4,562	4,357
Current Liabilities
Short-term borrowings		0	216
Long-term debt due within one year		79	83
Accounts payable		111	82
Accrued expenses		45	35
Payable to affiliates, current		25	46
Regulatory Liability, Current		67	42
Customer deposits		34	35
Other		6	8
Total current liabilities		367	547
Long-term debt		1,415	1,217
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		626	603
Non-pension postretirement benefit obligations		13	14
Regulatory Liability, Noncurrent		588	593
Other		51	48
Total deferred credits and other liabilities		1,278	1,258
Total liabilities		3,060	3,022
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		914	764
Retained Earnings		588	571
Total shareholders’ equity		1,502	1,335
Member’s equity
Total liabilities and shareholders’ equity		4,562	4,357
Atlantic City Electric Company [Member]
Current Assets
Cash and cash equivalents		6	2
Restricted cash and cash equivalents		5	6
Accounts receivable, net
Customer		103	92
Other		50	56
Inventories, net
Inventories, net		25	29
Regulatory Assets, Current		60	71
Prepaid Taxes		36	0
Other		7	2
Total current assets		292	258
Property, plant and equipment, net		2,831	2,706
Deferred debits and other assets
Regulatory Assets, Noncurrent		381	359
Long-term note receivable		0	4
Prepaid pension asset		73	73
Other		42	45
Total deferred debits and other assets		496	481
Total assets	[4]	3,619	3,445
Current Liabilities
Short-term borrowings		247	108
Long-term debt due within one year		275	281
Accounts payable		143	118
Accrued expenses		35	33
Payable to affiliates, current		25	29
Regulatory Liability, Current		29	11
Customer deposits		26	31
Other		9	8
Total current liabilities		789	619
Long-term debt		832	840
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		501	493
Non-pension postretirement benefit obligations		14	14
Regulatory Liability, Noncurrent		418	411
Other		26	25
Total deferred credits and other liabilities		959	943
Total liabilities	[4]	2,580	2,402
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		912	912
Retained Earnings		127	131
Total shareholders’ equity		1,039	1,043
Member’s equity
Total liabilities and shareholders’ equity		3,619	3,445
Variable Interest Entity, Consolidated, Assets, Not Pledged		25	29
Variable Interest Entity, Consolidated, Liabilities, No Recourse		$ 76	$ 90

[1] Exelon’s consolidated assets include $9,612 million and $9,597 million at June 30, 2018 and December 31, 2017, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $3,544 million and $3,618 million at June 30, 2018 and December 31, 2017, respectively, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 3 — Variable Interest Entities for additional information.

[2] Generation’s consolidated assets include $9,575 million and $9,556 million at June 30, 2018 and December 31, 2017, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Generation’s consolidated liabilities include $3,456 million and $3,516 million at June 30, 2018 and December 31, 2017, respectively, of certain VIEs for which the VIE creditors do not have recourse to Generation. See Note 3 — Variable Interest Entities for additional information.

[3] PHI’s consolidated total assets include $37 million and $41 million at June 30, 2018 and December 31, 2017, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $88 million and $102 million at June 30, 2018 and December 31, 2017, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 3 — Variable Interest Entities for additional information.

[4] ACE’s consolidated total assets include $25 million and $29 million at June 30, 2018 and December 31, 2017, respectively, of ACE's consolidated VIE that can only be used to settle the liabilities of the VIE. ACE’s consolidated total liabilities include $76 million and $90 million at June 30, 2018 and December 31, 2017, respectively, of ACE's consolidated VIE for which the VIE creditors do not have recourse to ACE. See Note 3 — Variable Interest Entities for additional information.