Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents		$ 1,918	$ 898
Restricted cash and cash equivalents		240	207
Accounts receivable, net
Customer		4,239	4,445
Other		1,246	1,132
Mark-to-market derivative assets, current		696	976
Unamortized energy contract assets, current		42	60
Inventories, net
Energy Related Inventory, Other Fossil Fuel		349	340
Materials and Supplies		1,316	1,311
Regulatory Assets, Current		1,340	1,267
Assets Held for Sale		910	0
Other		1,177	1,260
Total current assets		13,473	11,896
Property, plant and equipment, net		75,840	74,202
Deferred debits and other assets
Regulatory Assets, Noncurrent		8,002	8,021
Nuclear decommissioning trust funds		12,464	13,272
Investments		649	640
Goodwill		6,677	6,677
Mark-to-market derivative assets, noncurrent		449	337
Unamortized energy contract assets, noncurrent		371	395
Other		1,560	1,330
Total deferred debits and other assets		30,172	30,672
Total assets	[1]	119,485	116,770
Current Liabilities
Short-term borrowings		834	929
Long-term debt due within one year		771	2,088
Accounts payable		3,348	3,532
Accrued expenses		1,964	1,837
Payable to affiliates, current		5	5
Regulatory Liability, Current		689	523
Mark-to-market derivative liabilities, current		329	232
Unamortized energy contract liabilities, current		158	231
Renewable energy credit obligation		256	352
PHI merger related obligation		63	87
Liabilities Held for Sale		788	0
Other		935	982
Total current liabilities		10,140	10,798
Long-term debt		34,519	32,176
Long-term debt to financing trust		390	389
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		11,702	11,235
Asset Retirement Obligations, Noncurrent		9,747	10,029
Pension obligations		3,385	3,736
Non-pension postretirement benefit obligations		2,155	2,093
Spent nuclear fuel obligation		1,164	1,147
Regulatory Liability, Noncurrent		9,756	9,865
Mark-to-market derivative liabilities, noncurrent		482	409
Unamortized energy contract liabilities, noncurrent		497	609
Other		2,160	2,097
Total deferred credits and other liabilities		41,048	41,220
Total liabilities	[1]	86,097	84,583
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		19,063	18,964
Treasury stock, at cost (2 shares at September 30, 2018 and December 31, 2017)		(123)	(123)
Retained Earnings		14,949	14,081
Accumulated other comprehensive loss, net		(2,869)	(3,026)
Total shareholders’ equity		31,020	29,896
Member’s equity
Noncontrolling Interests		2,368	2,291
Total equity		33,388	32,187
Total liabilities and shareholders’ equity		119,485	116,770
Variable Interest Entity, Consolidated, Assets, Not Pledged		9,804	9,597
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,606	3,618
Exelon Generation Co L L C [Member]
Current Assets
Cash and cash equivalents		1,187	416
Restricted cash and cash equivalents		152	138
Accounts receivable, net
Customer		2,545	2,697
Other		278	321
Mark-to-market derivative assets, current		696	976
Receivable from affiliates, current		182	140
Unamortized energy contract assets, current		42	60
Inventories, net
Energy Related Inventory, Other Fossil Fuel		255	264
Materials and Supplies		948	937
Assets Held for Sale		910	0
Other		854	933
Total current assets		8,049	6,882
Property, plant and equipment, net		24,168	24,906
Deferred debits and other assets
Nuclear decommissioning trust funds		12,464	13,272
Investments		433	433
Goodwill		47	47
Mark-to-market derivative assets, noncurrent		449	334
Prepaid pension asset		1,472	1,502
Unamortized energy contract assets, noncurrent		370	395
Deferred income taxes		25	16
Other		730	670
Total deferred debits and other assets		15,990	16,669
Total assets	[2]	48,207	48,457
Current Liabilities
Short-term borrowings		0	2
Long-term debt due within one year		336	346
Accounts payable		1,450	1,773
Accrued expenses		1,200	1,022
Payable to affiliates, current		144	123
Borrowings from Exelon intercompany money pool		0	54
Mark-to-market derivative liabilities, current		305	211
Unamortized energy contract liabilities, current		33	43
Renewable energy credit obligation		256	352
Liabilities Held for Sale		788	0
Other		255	265
Total current liabilities		4,767	4,191
Long-term debt		7,605	7,734
Long-term debt to affiliate		901	910
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,532	3,811
Asset Retirement Obligations, Noncurrent		9,521	9,844
Non-pension postretirement benefit obligations		903	916
Spent nuclear fuel obligation		1,164	1,147
Payables to affiliates, noncurrent		2,959	3,065
Mark-to-market derivative liabilities, noncurrent		237	174
Unamortized energy contract liabilities, noncurrent		23	48
Other		635	658
Total deferred credits and other liabilities		18,974	19,663
Total liabilities	[2]	32,247	32,498
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Retained Earnings		4,214	4,349
Accumulated other comprehensive loss, net		(31)	(37)
Member’s equity
Membership Interest		9,411	9,357
Total members' equity		13,594	13,669
Noncontrolling Interests		2,366	2,290
Total equity		15,960	15,959
Total liabilities and shareholders’ equity		48,207	48,457
Variable Interest Entity, Consolidated, Assets, Not Pledged		9,768	9,556
Variable Interest Entity, Consolidated, Liabilities, No Recourse		3,528	3,516
Commonwealth Edison Co [Member]
Current Assets
Cash and cash equivalents		124	76
Restricted cash and cash equivalents		12	5
Accounts receivable, net
Customer		590	559
Other		450	266
Receivable from affiliates, current		13	13
Inventories, net
Inventories, net		146	152
Regulatory Assets, Current		256	225
Other		94	68
Total current assets		1,685	1,364
Property, plant and equipment, net		21,642	20,723
Deferred debits and other assets
Regulatory Assets, Noncurrent		1,229	1,054
Investments		6	6
Goodwill		2,625	2,625
Receivable from affiliate, noncurrent		2,469	2,528
Prepaid pension asset		1,083	1,188
Other		380	238
Total deferred debits and other assets		7,792	7,639
Total assets		31,119	29,726
Current Liabilities
Long-term debt due within one year		300	840
Accounts payable		576	568
Accrued expenses		253	327
Payable to affiliates, current		82	74
Regulatory Liability, Current		320	249
Mark-to-market derivative liabilities, current		24	21
Customer deposits		111	112
Other		90	103
Total current liabilities		1,756	2,294
Long-term debt		7,800	6,761
Long-term debt to financing trust		205	205
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		3,744	3,469
Asset Retirement Obligations, Noncurrent		115	111
Non-pension postretirement benefit obligations		206	219
Regulatory Liability, Noncurrent		6,318	6,328
Mark-to-market derivative liabilities, noncurrent		235	235
Other		633	562
Total deferred credits and other liabilities		11,251	10,924
Total liabilities		21,012	20,184
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,588	1,588
Other paid-in capital		7,209	6,822
Retained Earnings, Unappropriated		(1,639)	(1,639)
Retained Earnings, Appropriated		2,949	2,771
Total shareholders’ equity		10,107	9,542
Member’s equity
Total liabilities and shareholders’ equity		31,119	29,726
PECO Energy Co [Member]
Current Assets
Cash and cash equivalents		102	271
Restricted cash and cash equivalents		5	4
Accounts receivable, net
Customer		307	327
Other		190	105
Inventories, net
Energy Related Inventory, Other Fossil Fuel		39	31
Materials and Supplies		35	30
Regulatory Assets, Current		84	29
Prepaid Taxes		32	8
Other		19	17
Total current assets		813	822
Property, plant and equipment, net		8,461	8,053
Deferred debits and other assets
Regulatory Assets, Noncurrent		448	381
Investments		26	25
Receivable from affiliate, noncurrent		489	537
Prepaid pension asset		350	340
Other		34	12
Total deferred debits and other assets		1,347	1,295
Total assets		10,621	10,170
Current Liabilities
Long-term debt due within one year		0	500
Accounts payable		387	370
Accrued expenses		89	114
Payable to affiliates, current		53	53
Regulatory Liability, Current		159	141
Customer deposits		67	66
Other		31	23
Total current liabilities		786	1,267
Long-term debt		3,083	2,403
Long-term debt to financing trust		184	184
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,909	1,789
Asset Retirement Obligations, Noncurrent		27	27
Non-pension postretirement benefit obligations		288	288
Regulatory Liability, Noncurrent		581	549
Other		79	86
Total deferred credits and other liabilities		2,884	2,739
Total liabilities		6,937	6,593
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		2,560	2,489
Retained Earnings		1,124	1,087
Accumulated other comprehensive loss, net		0	1
Total shareholders’ equity		3,684	3,577
Member’s equity
Total liabilities and shareholders’ equity		10,621	10,170
Baltimore Gas and Electric Company [Member]
Current Assets
Cash and cash equivalents		113	17
Restricted cash and cash equivalents		3	1
Accounts receivable, net
Customer		296	375
Other		96	94
Receivable from affiliates, current		0	1
Inventories, net
Materials and Supplies		39	40
Gas Held in Storage		46	37
Regulatory Assets, Current		195	174
Prepaid Taxes		0	69
Other		10	3
Total current assets		798	811
Property, plant and equipment, net		8,039	7,602
Deferred debits and other assets
Regulatory Assets, Noncurrent		402	397
Investments		5	5
Prepaid pension asset		290	285
Other		7	4
Total deferred debits and other assets		704	691
Total assets		9,541	9,104
Current Liabilities
Short-term borrowings		0	77
Accounts payable		277	265
Accrued expenses		146	164
Payable to affiliates, current		47	52
Regulatory Liability, Current		95	62
Customer deposits		119	116
Other		23	24
Total current liabilities		707	760
Long-term debt		2,876	2,577
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,345	1,244
Asset Retirement Obligations, Noncurrent		24	23
Non-pension postretirement benefit obligations		200	202
Regulatory Liability, Noncurrent		1,070	1,101
Other		75	56
Total deferred credits and other liabilities		2,714	2,626
Total liabilities		6,297	5,963
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,623	1,605
Retained Earnings		1,621	1,536
Total shareholders’ equity		3,244	3,141
Member’s equity
Total liabilities and shareholders’ equity		9,541	9,104
Pepco Holdings LLC [Member]
Current Assets
Cash and cash equivalents		153	30
Restricted cash and cash equivalents		42	42
Accounts receivable, net
Customer		500	486
Other		266	206
Receivable from affiliates, current		0	0
Inventories, net
Materials and Supplies		149	151
Gas Held in Storage		9	7
Regulatory Assets, Current		521	554
Other		60	75
Total current assets		1,700	1,551
Property, plant and equipment, net		13,167	12,498
Deferred debits and other assets
Regulatory Assets, Noncurrent		2,374	2,493
Investments		133	132
Long-term note receivable		0	4
Goodwill		4,005	4,005
Prepaid pension asset		499	490
Deferred income taxes		12	4
Other		67	70
Total deferred debits and other assets		7,090	7,198
Total assets	[3]	21,957	21,247
Current Liabilities
Short-term borrowings		334	350
Long-term debt due within one year		117	396
Accounts payable		505	348
Accrued expenses		269	261
Payable to affiliates, current		102	90
Borrowings from Exelon intercompany money pool		10	0
Regulatory Liability, Current		99	56
Unamortized energy contract liabilities, current		125	188
Customer deposits		113	119
Merger related obligation		38	42
Other		57	81
Total current liabilities		1,769	1,931
Long-term debt		5,972	5,478
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		2,243	2,070
Asset Retirement Obligations, Noncurrent		53	16
Non-pension postretirement benefit obligations		102	105
Regulatory Liability, Noncurrent		1,783	1,872
Unamortized energy contract liabilities, noncurrent		474	561
Other		395	389
Total deferred credits and other liabilities		5,050	5,013
Total liabilities	[3]	12,791	12,422
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Retained Earnings		94	(10)
Member’s equity
Membership Interest		9,072	8,835
Total members' equity		9,166	8,825
Total equity		9,166	8,825
Total liabilities and shareholders’ equity		21,957	21,247
Variable Interest Entity, Consolidated, Assets, Not Pledged		36	41
Variable Interest Entity, Consolidated, Liabilities, No Recourse		78	102
Potomac Electric Power Company [Member]
Current Assets
Cash and cash equivalents		12	5
Restricted cash and cash equivalents		35	35
Accounts receivable, net
Customer		235	250
Other		102	87
Inventories, net
Inventories, net		81	87
Regulatory Assets, Current		284	213
Other		9	33
Total current assets		758	710
Property, plant and equipment, net		6,337	6,001
Deferred debits and other assets
Regulatory Assets, Noncurrent		662	678
Investments		105	102
Prepaid pension asset		318	322
Other		19	19
Total deferred debits and other assets		1,104	1,121
Total assets		8,199	7,832
Current Liabilities
Short-term borrowings		64	26
Long-term debt due within one year		14	19
Accounts payable		234	139
Accrued expenses		141	137
Payable to affiliates, current		70	74
Regulatory Liability, Current		5	3
Customer deposits		53	54
Merger related obligation		38	42
Current portion of DC PLUG obligation		30	28
Other		9	28
Total current liabilities		658	550
Long-term debt		2,611	2,521
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,139	1,063
Non-pension postretirement benefit obligations		31	36
Regulatory Liability, Noncurrent		759	829
Other		337	300
Total deferred credits and other liabilities		2,266	2,228
Total liabilities		5,535	5,299
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		1,555	1,470
Retained Earnings		1,109	1,063
Total shareholders’ equity		2,664	2,533
Member’s equity
Total liabilities and shareholders’ equity		8,199	7,832
Delmarva Power and Light Company [Member]
Current Assets
Cash and cash equivalents		110	2
Restricted cash and cash equivalents		0	0
Accounts receivable, net
Customer		121	146
Other		53	38
Inventories, net
Materials and Supplies		37	36
Gas Held in Storage		9	7
Regulatory Assets, Current		66	69
Other		18	27
Total current assets		414	325
Property, plant and equipment, net		3,748	3,579
Deferred debits and other assets
Regulatory Assets, Noncurrent		235	245
Goodwill		8	8
Prepaid pension asset		188	193
Other		8	7
Total deferred debits and other assets		439	453
Total assets		4,601	4,357
Current Liabilities
Short-term borrowings		0	216
Long-term debt due within one year		79	83
Accounts payable		104	82
Accrued expenses		52	35
Payable to affiliates, current		30	46
Regulatory Liability, Current		67	42
Customer deposits		35	35
Other		6	8
Total current liabilities		373	547
Long-term debt		1,415	1,217
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		645	603
Non-pension postretirement benefit obligations		15	14
Regulatory Liability, Noncurrent		587	593
Other		49	48
Total deferred credits and other liabilities		1,296	1,258
Total liabilities		3,084	3,022
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		914	764
Retained Earnings		603	571
Total shareholders’ equity		1,517	1,335
Member’s equity
Total liabilities and shareholders’ equity		4,601	4,357
Atlantic City Electric Company [Member]
Current Assets
Cash and cash equivalents		11	2
Restricted cash and cash equivalents		7	6
Accounts receivable, net
Customer		144	92
Other		59	56
Receivable from affiliates, current		0	0
Inventories, net
Inventories, net		31	29
Regulatory Assets, Current		44	71
Prepaid Taxes		0	0
Other		21	2
Total current assets		317	258
Property, plant and equipment, net		2,883	2,706
Deferred debits and other assets
Regulatory Assets, Noncurrent		383	359
Long-term note receivable		0	4
Prepaid pension asset		70	73
Other		41	45
Total deferred debits and other assets		494	481
Total assets	[4]	3,694	3,445
Current Liabilities
Short-term borrowings		270	108
Long-term debt due within one year		22	281
Accounts payable		149	118
Accrued expenses		38	33
Payable to affiliates, current		25	29
Regulatory Liability, Current		27	11
Customer deposits		26	31
Other		9	8
Total current liabilities		566	619
Long-term debt		1,078	840
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		534	493
Non-pension postretirement benefit obligations		16	14
Regulatory Liability, Noncurrent		401	411
Other		26	25
Total deferred credits and other liabilities		977	943
Total liabilities	[4]	2,621	2,402
Commitments and contingencies
Stockholders' Equity Attributable to Parent
Common stock		912	912
Retained Earnings		161	131
Total shareholders’ equity		1,073	1,043
Member’s equity
Total liabilities and shareholders’ equity		3,694	3,445
Variable Interest Entity, Consolidated, Assets, Not Pledged		26	29
Variable Interest Entity, Consolidated, Liabilities, No Recourse		$ 68	$ 90

[1] Exelon’s consolidated assets include $9,804 million and $9,597 million at September 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 $3,606 million and $3,618 million at September 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 $9,768 million and $9,556 million at September 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 $3,528 million and $3,516 million at September 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 $36 million and $41 million at September 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 $78 million and $102 million at September 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 $26 million and $29 million at September 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 $68 million and $90 million at September 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.