Segment Information - Analysis and Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions		3 Months Ended									9 Months Ended	12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Mar. 23, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Segment Reporting Information [Line Items]
Competitive Energy Revenue												$ 13,960		$ 15,200		$ 13,773
Electric operating revenues												13,869		9,876		9,467
Natural gas operating revenues												1,166		1,176		1,325
Other Operating Income												211		757		154
Revenue from Purchased Oil and Gas												2,146		2,433		2,704
Operating revenues from affiliates												10		9		23
Depreciation and amortization												3,936		2,450		2,314
Operating Expenses	[1]											28,200		25,056		25,039
Equity in earnings (losses) of unconsolidated affiliates												0		0		(20)
Income (Loss) from Equity Method Investments												(24)		(7)		0
Interest expense, net												1,536		1,033		1,065
Income (loss) from continuing operations before income taxes												1,989		3,330		2,486
Income taxes												761		1,073		666
Net income												1,204		2,250		1,820
Assets	[2]	$ 114,904					$ 95,384				$ 114,904	114,904		95,384
Utilities Operating Expense, Taxes	[3]											753		474		456
Payments to Acquire Property, Plant, and Equipment												8,553		7,624		6,077
Sales Revenue, Services, Other												7		5		6
PECO Energy Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[4]											1		1		1
Pepco Holdings LLC [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]					$ 1,096								4,770		4,614
Natural gas operating revenues	[5]					57								165		194
Net income						19								327		242
Assets							16,188							16,188
Sales Revenue, Services, Other	[5]					0								0		0
Pepco Holdings LLC [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]										3,506
Natural gas operating revenues	[5]										92
Net income											(61)
Assets		21,025									21,025	21,025
Sales Revenue, Services, Other	[5]										45
Corporate, Non-Segment [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue	[6]											0		0		0
Electric operating revenues	[6]											0		0		0
Natural gas operating revenues	[6]											0		0		0
Other Operating Income	[6]											0		0		0
Revenue from Purchased Oil and Gas	[6]											0		0		0
Depreciation and amortization	[6]											74		63		53
Operating Expenses	[1],[6]											1,928		1,444		1,353
Equity in earnings (losses) of unconsolidated affiliates	[6]															0
Income (Loss) from Equity Method Investments	[6]											1		1
Interest expense, net	[6]											290		123		169
Income (loss) from continuing operations before income taxes	[6]											(555)		(219)		(227)
Income taxes	[6]											(156)		(41)		(63)
Net income	[6]											(398)		(177)		(164)
Assets	[6]	10,369					15,389				10,369	10,369		15,389
Payments to Acquire Property, Plant, and Equipment	[6]											113		65		95
Sales Revenue, Services, Other	[6]											1,648		1,372		1,285
Corporate, Non-Segment [Member] | Corporate and Other [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5],[7]					42								210		264
Natural gas operating revenues	[5],[7]					1								1		0
Depreciation and amortization	[7]					11								45		38
Operating Expenses	[7]					73								220		350
Interest expense, net	[7]					11								43		42
Income (loss) from continuing operations before income taxes	[7]					59								23		306
Income taxes	[7]					(16)								(48)		(228)
Net income	[7]					(44)								25		(78)
Assets	[7]						7,162							7,162
Payments to Acquire Property, Plant, and Equipment	[7]					11								34		79
Sales Revenue, Services, Other	[5],[7]					0								0		0
Corporate, Non-Segment [Member] | Corporate and Other [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5],[7]										5
Natural gas operating revenues	[5],[7]										0
Depreciation and amortization	[7]										43
Operating Expenses	[7]										33
Interest expense, net	[7]										12
Income (loss) from continuing operations before income taxes	[7]										(84)
Income taxes	[7]										(23)
Net income	[7]										(34)
Assets	[7]	10,804									10,804	10,804
Payments to Acquire Property, Plant, and Equipment	[7]										24
Sales Revenue, Services, Other	[5],[7]										45
Operating Segments [Member] | Atlantic City Electric Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]					268								1,295		1,210
Natural gas operating revenues	[5]					0								0		0
Depreciation and amortization						37								175		155
Operating Expenses						251								1,161		1,073
Interest expense, net						15								64		64
Income (loss) from continuing operations before income taxes						5								73		76
Income taxes						1								33		30
Net income						5								40		46
Assets							3,387							3,387
Payments to Acquire Property, Plant, and Equipment						93								300		225
Sales Revenue, Services, Other	[5]					0								0		0
Operating Segments [Member] | Atlantic City Electric Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]										989
Natural gas operating revenues	[5]										0
Depreciation and amortization											128
Operating Expenses											1,000
Interest expense, net											47
Income (loss) from continuing operations before income taxes											(51)
Income taxes											(5)
Net income											(47)
Assets		3,457									3,457	3,457
Payments to Acquire Property, Plant, and Equipment											218
Sales Revenue, Services, Other	[5]										0
Operating Segments [Member] | Delmarva Power and Light Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]					279								1,138		1,088
Natural gas operating revenues	[5]					56								164		194
Depreciation and amortization						37								148		122
Operating Expenses						284								1,137		1,075
Interest expense, net						12								50		48
Income (loss) from continuing operations before income taxes						43								125		169
Income taxes						17								49		65
Net income						26								76		104
Assets							3,969							3,969
Payments to Acquire Property, Plant, and Equipment						72								352		352
Sales Revenue, Services, Other	[5]					0								0		0
Operating Segments [Member] | Delmarva Power and Light Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]										850
Natural gas operating revenues	[5]										92
Depreciation and amortization											120
Operating Expenses											952
Interest expense, net											38
Income (loss) from continuing operations before income taxes											(30)
Income taxes											5
Net income											(35)
Assets		4,153									4,153	4,153
Payments to Acquire Property, Plant, and Equipment											277
Sales Revenue, Services, Other	[5]										0
Operating Segments [Member] | Potomac Electric Power Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]					511								2,129		2,055
Natural gas operating revenues	[5]					0								0		0
Depreciation and amortization						71								256		212
Operating Expenses						443								1,790		1,706
Interest expense, net						29								124		115
Income (loss) from continuing operations before income taxes						47								289		264
Income taxes						15								102		93
Net income						32								187		171
Assets							6,908							6,908
Payments to Acquire Property, Plant, and Equipment						97								544		567
Sales Revenue, Services, Other	[5]					0								0		0
Operating Segments [Member] | Potomac Electric Power Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]										1,675
Natural gas operating revenues	[5]										0
Depreciation and amortization											224
Operating Expenses											1,577
Interest expense, net											98
Income (loss) from continuing operations before income taxes											36
Income taxes											26
Net income											10
Assets		7,335									7,335	7,335
Payments to Acquire Property, Plant, and Equipment											489
Sales Revenue, Services, Other	[5]										0
Operating Segments [Member] | Pepco Holdings LLC [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization						152								624		526
Operating Expenses						1,048								4,308		4,203
Interest expense, net						65								280		269
Income (loss) from continuing operations before income taxes						36								481		380
Income taxes						17								163		138
Payments to Acquire Property, Plant, and Equipment						273								1,230		1,223
Operating Segments [Member] | Pepco Holdings LLC [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue	[6],[8]											0		0		0
Electric operating revenues	[6],[8]											3,506		0		0
Natural gas operating revenues	[6],[8]											92		0		0
Other Operating Income	[6],[8]											0		0		0
Revenue from Purchased Oil and Gas	[6],[8]											0		0		0
Depreciation and amortization											515	515	[8]	0	[8]	0	[8]
Operating Expenses											3,549	3,549	[6],[8]	0	[6],[8]	0	[6],[8]
Equity in earnings (losses) of unconsolidated affiliates	[8]															0
Income (Loss) from Equity Method Investments	[8]											0		0
Interest expense, net											195	195	[8]	0	[8]	0	[8]
Income (loss) from continuing operations before income taxes											(58)	(58)	[8]	0	[8]	0	[8]
Income taxes											3	3	[8]	0	[8]	0	[8]
Net income	[8]											(61)		0		0
Assets	[8]	21,025					0				21,025	21,025		0
Payments to Acquire Property, Plant, and Equipment											1,008	1,008	[8]	0	[8]	0	[8]
Sales Revenue, Services, Other	[6],[8]											45		0		0
Operating Segments [Member] | Exelon Generation Co L L C [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue	[9]											15,390		15,944		14,533
Electric operating revenues	[9]											0		0		0
Natural gas operating revenues	[9]											0		0		0
Other Operating Income	[9]											215		758		155
Revenue from Purchased Oil and Gas	[9]											2,146		2,433		2,705
Depreciation and amortization	[9]											1,879		1,054		967
Operating Expenses	[1],[9]											16,856		16,872		16,923
Equity in earnings (losses) of unconsolidated affiliates	[9]															(20)
Income (Loss) from Equity Method Investments	[9]											(25)		(8)
Interest expense, net	[9]											364		365		356
Income (loss) from continuing operations before income taxes	[9]											873		1,850		1,226
Income taxes	[9]											290		502		207
Net income	[9]											558		1,340		1,019
Assets	[9]	46,974					46,529				46,974	46,974		46,529
Payments to Acquire Property, Plant, and Equipment	[9]											3,078		3,841		3,012
Sales Revenue, Services, Other	[9]											0		0		0
Operating Segments [Member] | Commonwealth Edison Co [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue												0		0		0
Electric operating revenues												5,254		4,905		4,564
Natural gas operating revenues												0		0		0
Other Operating Income												0		0		0
Revenue from Purchased Oil and Gas												0		0		0
Depreciation and amortization												775		707		687
Operating Expenses	[1]											4,056		3,889		3,586
Equity in earnings (losses) of unconsolidated affiliates																0
Income (Loss) from Equity Method Investments												0		0
Interest expense, net												461		332		321
Income (loss) from continuing operations before income taxes												679		706		676
Income taxes												301		280		268
Net income												378		426		408
Assets		28,335					26,532				28,335	28,335		26,532
Payments to Acquire Property, Plant, and Equipment												2,734		2,398		1,689
Sales Revenue, Services, Other												0		0		0
Operating Segments [Member] | PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue												0		0		0
Electric operating revenues												2,531		2,486		2,448
Natural gas operating revenues												463		546		646
Other Operating Income												0		0		0
Revenue from Purchased Oil and Gas												0		0		0
Depreciation and amortization												270		260		236
Operating Expenses	[1]											2,292		2,404		2,522
Equity in earnings (losses) of unconsolidated affiliates																0
Income (Loss) from Equity Method Investments												0		0
Interest expense, net												123		114		113
Income (loss) from continuing operations before income taxes												587		521		466
Income taxes												149		143		114
Net income												438		378		352
Assets		10,831					10,367				10,831	10,831		10,367
Payments to Acquire Property, Plant, and Equipment												686		601		661
Sales Revenue, Services, Other												0		0		0
Operating Segments [Member] | Baltimore Gas and Electric Company [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue	[10]											0		0		0
Electric operating revenues	[10]											2,609		2,490		2,460
Natural gas operating revenues	[10]											624		645		705
Other Operating Income	[10]											0		0		0
Revenue from Purchased Oil and Gas	[10]											0		0		0
Depreciation and amortization	[10]											423		366		371
Operating Expenses	[1],[10]											2,683		2,578		2,726
Equity in earnings (losses) of unconsolidated affiliates	[10]															0
Income (Loss) from Equity Method Investments	[10]											0		0
Interest expense, net	[10]											103		99		106
Income (loss) from continuing operations before income taxes	[10]											468		477		351
Income taxes	[10]											174		189		140
Net income	[10]											294		288		211
Assets	[10]	8,704					8,295				8,704	8,704		8,295
Payments to Acquire Property, Plant, and Equipment	[10]											934		719		620
Sales Revenue, Services, Other	[10]											0		0		0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Competitive Energy Revenue												(1,430)		(744)		(760)
Electric operating revenues												(31)		(5)		(5)
Natural gas operating revenues												(13)		(15)		(26)
Other Operating Income												(4)		(1)		(1)
Revenue from Purchased Oil and Gas												0		0		(1)
Operating revenues from affiliates	[8]											5		5		6
Depreciation and amortization												0		0		0
Operating Expenses	[1]											(3,164)		(2,131)		(2,071)
Equity in earnings (losses) of unconsolidated affiliates																0
Income (Loss) from Equity Method Investments												0		0
Interest expense, net												0		0		0
Income (loss) from continuing operations before income taxes												(5)		(5)		(6)
Income taxes												0		0		0
Net income												(5)		(5)		(6)
Assets		(11,334)					(11,728)				(11,334)	(11,334)		(11,728)
Payments to Acquire Property, Plant, and Equipment												0		0		0
Sales Revenue, Services, Other												(1,686)		(1,367)		(1,279)
Intersegment Eliminations [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]					(4)								(2)		(3)
Natural gas operating revenues	[5]					0								0		0
Net income						0								(1)		(1)
Assets							(5,238)							(5,238)
Sales Revenue, Services, Other	[5]					0								0		0
Intersegment Eliminations [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues	[5]										(13)
Natural gas operating revenues	[5]										0
Net income											45
Assets		(4,724)									(4,724)	(4,724)
Sales Revenue, Services, Other	[5]										0
Intersegment Eliminations [Member] | Atlantic City Electric Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates						1								4		4
Intersegment Eliminations [Member] | Atlantic City Electric Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates											2
Intersegment Eliminations [Member] | Delmarva Power and Light Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates						2								6		7
Intersegment Eliminations [Member] | Delmarva Power and Light Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates											5
Intersegment Eliminations [Member] | Potomac Electric Power Company [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates						1								5		5
Intersegment Eliminations [Member] | Potomac Electric Power Company [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates											4
Intersegment Eliminations [Member] | Pepco Holdings LLC [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates						0								0		0
Intersegment Eliminations [Member] | Pepco Holdings LLC [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates											45	45	[1],[8]	0	[1],[8]	0	[1],[8]
Intersegment Eliminations [Member] | Exelon Generation Co L L C [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1,428		745	[8],[9]	762	[8],[9]
Intersegment Eliminations [Member] | Commonwealth Edison Co [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												15		4	[8]	4	[8]
Intersegment Eliminations [Member] | PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[8]													2		2
Intersegment Eliminations [Member] | Baltimore Gas and Electric Company [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[8],[10]													14		25
Intersegment Eliminations [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[1]											1,647	[10]	1,367	[8]	1,280	[8]
Intersegment Eliminations [Member] | Corporate and Other [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[7]					0								0		0
Intersegment Eliminations [Member] | Corporate and Other [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[7]										47
Intersegment Eliminations [Member] | Generation Midwest [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												10		(2)		(13)
Intersegment Eliminations [Member] | Segment Elimination [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[8]											(3,159)		(2,127)		(2,067)
Intersegment Eliminations [Member] | Segment Elimination [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates						(4)								(15)		(16)
Depreciation and amortization						(4)								0		(1)
Operating Expenses						(3)								0		(1)
Interest expense, net						(2)								(1)		0
Income (loss) from continuing operations before income taxes						(118)								(29)		(435)
Income taxes						0								27		178
Payments to Acquire Property, Plant, and Equipment						0								0		0
Intersegment Eliminations [Member] | Segment Elimination [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates											(13)
Depreciation and amortization											0
Operating Expenses											(13)
Interest expense, net											0
Income (loss) from continuing operations before income taxes											71
Income taxes											0
Payments to Acquire Property, Plant, and Equipment											0
Exelon Generation Co L L C [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1,439		749		779
Equity in earnings (losses) of unconsolidated affiliates												(25)		(8)		0
Income (Loss) from Equity Method Investments										$ 19		0		0		(20)
Income (loss) from continuing operations before income taxes												873		1,850		1,226
Income taxes												290		502		207
Net income												558		1,340		1,019
Assets	[11]	46,974					46,529				46,974	46,974		46,529
Utilities Operating Expense, Taxes	[3]											122		105		89
Payments to Acquire Property, Plant, and Equipment												3,078		3,841		3,012
Exelon Generation Co L L C [Member] | PECO Energy Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[12]											290		224		198
Exelon Generation Co L L C [Member] | Baltimore Gas And Electric Company Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[13]											608		502		387
Exelon Generation Co L L C [Member] | Commonwealth Edison Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[14]											47		18		176
Exelon Generation Co L L C [Member] | Potomac Electric Power Company [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[13]											295
Exelon Generation Co L L C [Member] | Delmarva Power and Light Company [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[13]											154
Exelon Generation Co L L C [Member] | Atlantic City Electric Company [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[13]											37
Exelon Generation Co L L C [Member] | Intersegment Eliminations [Member] | Commonwealth Edison Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates	[14]															7
Commonwealth Edison Co [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												5,239		4,901		4,560
Operating revenues from affiliates												15		4		4
Income (Loss) from Equity Method Investments												0		0
Income taxes												301		280		268
Net income		80	$ 37	$ 145	$ 115		87	$ 149	$ 99	$ 90		378		426		408
Assets		28,335					26,532				28,335	28,335		26,532
Utilities Operating Expense, Taxes	[3]											242		236		238
Payments to Acquire Property, Plant, and Equipment												2,734		2,398		1,689
Commonwealth Edison Co [Member] | PECO Energy Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1
PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												2,524		2,485		2,446
Natural gas operating revenues												462		545		646
Operating revenues from affiliates												8		2		2
Income (Loss) from Equity Method Investments												0		0
Income (loss) from continuing operations before income taxes												587		521		466
Income taxes												149		143		114
Net income												438		378		352
Assets		10,831					10,367				10,831	10,831		10,367
Utilities Operating Expense, Taxes	[3]											136		133		128
Payments to Acquire Property, Plant, and Equipment												686		601		661
PECO Energy Co [Member] | Commonwealth Edison Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1
PECO Energy Co [Member] | Exelon Generation Co L L C [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												8
Baltimore Gas and Electric Company [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												2,603		2,490		2,460
Natural gas operating revenues												609		631		680
Operating revenues from affiliates												21		14		25
Income (Loss) from Equity Method Investments												0		0
Income (loss) from continuing operations before income taxes												468		477		351
Income taxes												174		189		140
Net income												294		288		211
Assets	[15]	8,704					8,295				8,704	8,704		8,295
Utilities Operating Expense, Taxes	[3]											85		85		86
Payments to Acquire Property, Plant, and Equipment												934		719		620
Baltimore Gas and Electric Company [Member] | PECO Energy Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1
Baltimore Gas and Electric Company [Member] | Commonwealth Edison Co Affiliate [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates												1
Pepco Holdings LLC [Member] | Predecessor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues						1,096								4,770		4,614
Natural gas operating revenues						57								165		194
Operating revenues from affiliates						0								0		0
Income (Loss) from Equity Method Investments						0								0
Income (loss) from continuing operations before income taxes						36								481		380
Income taxes						17								163		138
Net income						19								327		242
Assets	[16]						16,188							16,188
Utilities Operating Expense, Taxes	[3]					78								326		324
Payments to Acquire Property, Plant, and Equipment						$ 273								1,230		1,223
Pepco Holdings LLC [Member] | Successor [Member]
Segment Reporting Information [Line Items]
Electric operating revenues											3,506
Natural gas operating revenues											92
Operating revenues from affiliates											45
Income (Loss) from Equity Method Investments											0
Income (loss) from continuing operations before income taxes											(58)
Income taxes											3
Net income											(61)
Assets	[16]	21,025									21,025	21,025
Utilities Operating Expense, Taxes	[3]										253
Payments to Acquire Property, Plant, and Equipment											1,008
Potomac Electric Power Company [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												2,181		2,124		2,050
Operating revenues from affiliates												5		5		5
Income (Loss) from Equity Method Investments												0		0
Income (loss) from continuing operations before income taxes												83		289		264
Income taxes												41		102		93
Net income												42		187		171
Assets		7,335					6,908				7,335	7,335		6,908
Utilities Operating Expense, Taxes	[3]											312		308		307
Payments to Acquire Property, Plant, and Equipment												586		544		567
Delmarva Power and Light Company [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												1,122		1,132		1,081
Natural gas operating revenues												148		164		194
Operating revenues from affiliates												7		6		7
Income (Loss) from Equity Method Investments												0		0
Income (loss) from continuing operations before income taxes												13		125		169
Income taxes												22		49		65
Net income												(9)		76		104
Assets		4,153					3,969				4,153	4,153		3,969
Utilities Operating Expense, Taxes	[3]											18		18		17
Payments to Acquire Property, Plant, and Equipment												349		352		352
Atlantic City Electric Company [Member]
Segment Reporting Information [Line Items]
Electric operating revenues												1,254		1,291		1,206
Operating revenues from affiliates												3		4		4
Income (Loss) from Equity Method Investments												0		0
Income (loss) from continuing operations before income taxes												(46)		73		76
Income taxes												(4)		33		30
Net income												(42)		40		46
Assets	[17]	$ 3,457					$ 3,387				$ 3,457	3,457		3,387
Utilities Operating Expense, Taxes	[3]											0		0		0
Payments to Acquire Property, Plant, and Equipment												$ 311		$ 300		$ 225

[1] d)Intersegment revenues exclude sales to unconsolidated affiliates. The intersegment profit associated with Generation’s sale of certain products and services by and between Exelon’s segments is not eliminated in consolidation due to the recognition of intersegment profit in accordance with regulatory accounting guidance. For Exelon, these amounts are included in operating revenues in the Consolidated Statements of Operations and Comprehensive Income.

[2] Exelon’s consolidated assets include $8,893 million and $8,268 million at December 31, 2016 and December 31, 2015, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $3,356 million and $3,264 million at December 31, 2016 and December 31, 2015, respectively, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 2–Variable Interest Entities.

[3] Generation’s utility tax represents gross receipts tax related to its retail operations and ComEd’s, PECO’s, BGE’s, Pepco's, DPL's and ACE's utility taxes represent municipal and state utility taxes and gross receipts taxes related to their operating revenues. The offsetting collection of utility taxes from customers is recorded in revenues on the Registrants’ Consolidated Statements of Operations and Comprehensive Income.

[4] The intersegment profit associated with the sale of certain products and services by and between Exelon’s segments is not eliminated in consolidation due to the recognition of intersegment profit in accordance with regulatory accounting guidance. For Exelon, these amounts are included in operating revenues in the Consolidated Statements of Operations. See Note 3—Regulatory Matters for additional information.

[5] Includes gross utility tax receipts from customers. The offsetting remittance of utility taxes to the governing bodies is recorded in expenses on the Registrants’ Consolidated Statements of Operations and Comprehensive Income. See Note 25 — Supplemental Financial Information for total utility taxes for the year ended December 31, 2016 and 2015

[6] (c)For the years ended December 31, 2016, 2015 and 2014, utility taxes of $122 million, $105 million and $89 million, respectively, are included in revenues and expenses for Generation. For the years ended December 31, 2016, 2015 and 2014, utility taxes of $242 million, $236 million and $238 million, respectively, are included in revenues and expenses for ComEd. For the years ended December 31, 2016, 2015 and 2014, utility taxes of $136 million, $133 million and $128 million, respectively, are included in revenues and expenses for PECO. For the years ended December 31, 2016, 2015 and 2014, utility taxes of $85 million, $85 million and $86 million are included in revenues and expenses for BGE, respectively.

[7] Other primarily includes PHI’s corporate operations, shared service entities and other financing and investment activities. For the predecessor periods presented, Other includes the activity of PHI’s unregulated businesses which were distributed to Exelon and Generation as a result of the PHI Merger.

[8] Amounts included represent activity for PHI's successor period, March 24, 2016 through December 31, 2016. PHI includes the three reportable segments: Pepco, DPL and ACE. See tables below for PHI's predecessor periods, including Pepco, DPL and ACE, for January 1, 2016 to March 23, 2016 and for the years ended December 31, 2015

[9] Generation includes the six reportable segments shown below: Mid-Atlantic, Midwest, New England, New York, ERCOT and Other Power Regions. For the year ended December 31, 2016, intersegment revenues for Generation include revenue from sales to PECO of $290 million, sales to BGE of $608 million, sales to Pepco of $295 million, sales to DPL of $154 million and sales to ACE of $37 million in the Mid-Atlantic region, and sales to ComEd of $47 million in the Midwest region, which eliminate upon consolidation. For the year ended December 31, 2015, intersegment revenues for Generation include revenue from sales to PECO of $224 million and sales to BGE of $502 million in the Mid-Atlantic region, and sales to ComEd of $18 million in the Midwest region, which eliminate upon consolidation. For the year ended December 31, 2014, intersegment revenues for Generation include revenue from sales to PECO of $198 million and sales to BGE of $387 million in the Mid-Atlantic region, and sales to ComEd of $176 million in the Midwest region, net of $7 million related to the unrealized mark-to-market losses related to the ComEd swap, which eliminate upon consolidation.

[10] (b)Other primarily includes Exelon’s corporate operations, shared service entities and other financing and investment activities.

[11] Generation’s consolidated assets include $8,817 million and $8,235 million at December 31, 2016 and 2015, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Generation’s consolidated liabilities include $3,170 million and $3,135 million at December 31, 2016 and 2015, respectively, of certain VIEs for which the VIE creditors do not have recourse to Generation. See Note 2–Variable Interest Entities.

[12] Generation provides electric supply to PECO under contracts executed through PECO’s competitive procurement process. In addition, Generation has a ten-year agreement with PECO to sell solar AECs. See Note 3—Regulatory Matters for additional information.

[13] Generation provides a portion of BGE’s energy requirements under its MDPSC-approved market-based SOS and gas commodity programs. See Note 3—Regulatory Matters for additional information.

[14] Generation has an ICC-approved RFP contract with ComEd to provide a portion of ComEd’s electricity supply requirements. Generation also sells RECs to ComEd. In addition, Generation had revenue from ComEd associated with the settled portion of the financial swap contract established as part of the Illinois Settlement. See Note 3—Regulatory Matters for additional information.

[15] BGE’s consolidated assets include $26 million and $26 million at December 31, 2016 and December 31, 2015, respectively, of BGE’s consolidated VIE that can only be used to settle the liabilities of the VIE. BGE’s consolidated liabilities include $42 million and $122 million at December 31, 2016 and December 31, 2015, respectively, of BGE’s consolidated VIE for which the VIE creditors do not have recourse to BGE. See Note 2 - Variable Interest Entities.

[16] PHI’s consolidated total assets include $49 million and $30 million at December 31, 2016 and 2015, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $143 million and $172 million at December 31, 2016 and 2015, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 2 - Variable Interest Entities.

[17] ACE’s consolidated assets include $32 million and $30 million at December 31, 2016 and 2015, respectively, of ACE’s consolidated VIE that can only be used to settle the liabilities of the VIE. ACE’s consolidated liabilities include $126 million and $172 million at December 31, 2016 and 2015, respectively, of ACE’s consolidated VIE for which the VIE creditors do not have recourse to ACE. See Note 2 - Variable Interest Entities.