Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2016	Jun. 30, 2016	Mar. 23, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015
Gain (Loss) on Disposition of Assets	[1]							$ (26)
Operating revenues [Abstract]
Electrical Generation Revenue		$ 3,234			$ 4,080	$ 7,708		9,714
Gas Domestic Regulated Revenue		197			165	641		788
Operating revenues from affiliates		1			1
Regulated Operating Revenue		3,676			2,434	6,777		5,631
Electric Revenue		3,480			2,270	6,136		4,844
Revenues		6,910			6,514	14,485		15,345
Operating expenses
Purchased power		1,576			1,848	4,016		5,274
Cost of Purchased Power		878			601	1,692		1,645
Operating and maintenance		2,505			2,042	5,341		4,123
Depreciation and amortization		941			602	1,626		1,212
Taxes other than income		394			294	720		598
Total operating expenses		6,294			5,387	13,395		12,852
Gain (Loss) on Sale of Assets and Asset Impairment Charges		31			7	40		8
Operating income		647			1,134	1,130		2,501
Other income and (deductions)
Interest expense, net		(366)			(145)	(643)		(480)
Interest expense to affiliates		(10)			(10)	(20)		(21)
Other, net		144			(17)	258		64
Total other income and (deductions)		(232)			(172)	(405)		(437)
Income before income taxes		415			962	725		2,064
Income taxes		102			327	285		690
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions		(7)			(2)	(10)		(2)
Net income		306			633	430		1,372
Net income (loss) attributable to noncontrolling interests and preference stock dividends		39			(5)	(10)		41
Net income attributable to common shareholders		267			638	440		1,331
Other comprehensive income (loss), net of income taxes
Prior service benefit reclassified to periodic benefit cost		(12)			(11)	(23)		(23)
Actuarial loss reclassified to periodic benefit cost		46			55	93		110
Pension and non-pension postretirement benefit plan valuation adjustment		(1)			0	(3)		(29)
Unrealized (loss) gain on cash flow hedges		0			3	(7)		9
Unrealized loss on equity investments		(4)			0	(7)		0
Unrealized gain on marketable securities		2			0	0		0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		0			3	6		(9)
Other comprehensive income		31			50	59	[2]	58	[2]
Comprehensive income		337			683	489		1,430
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		39			(5)	(10)		41
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 298			$ 688	$ 499		$ 1,389
Average shares of common stock outstanding:
Weighted average common shares outstanding — basic		924			863	923		862
Average common shares outstanding — diluted		926			866	926		866
Earnings per average common share:
Earnings per share - basic (in usd per share)		$ 0.29			$ 0.74	$ 0.48		$ 1.54
Earnings per average common share - diluted
Earnings per share - diluted (in usd per share)		0.29			0.74	0.48		1.54
Dividends per common share (in usd per share)		$ 0.318			$ 0.31	$ 0.628		$ 0.62
PECO Energy Co [Member]
Operating revenues [Abstract]
Gas Domestic Regulated Revenue		$ 77			$ 79	$ 273		$ 386
Operating revenues from affiliates		2			0	4		1
Electric Revenue		585			582	1,228		1,259
Revenues		664			661	1,505		1,646
Operating expenses
Utilities Operating Expense, Purchased Power		130			161	295		377
Purchased power and fuel from affiliates		64			48	142		110
Utilities Operating Expense, Fuel Used		23			28	100		188
Operating and maintenance		157			166	333		363
Operating and maintenance from affiliates		33			26	72		51
Depreciation and amortization		67			69	134		131
Taxes other than income		38			39	80		80
Total operating expenses		512			537	1,156		1,300
Gain (Loss) on Disposition of Other Assets						0		1
Operating income		152			124	349		347
Other income and (deductions)
Interest expense, net		(28)			(25)	(56)		(50)
Interest expense to affiliates		(3)			(3)	(6)		(6)
Other, net		2			1	4		3
Total other income and (deductions)		(29)			(27)	(58)		(53)
Income before income taxes		123			97	291		294
Income taxes		23			27	67		85
Net income		100			70	224		209
Other comprehensive income (loss), net of income taxes
Other comprehensive income	[2]							0
Comprehensive income		100			70	224		209
Exelon Generation Co L L C [Member]
Gain (Loss) on Disposition of Assets								0
Operating revenues [Abstract]
Electrical Generation Revenue		3,231			4,079	7,702		9,709
Operating revenues from affiliates		358			153	627		365
Revenues		3,589			4,232	8,329		10,074
Operating expenses
Cost of Purchased Power		1,575			1,848	4,015		5,274
Purchased power and fuel from affiliates		2			1	5		8
Operating and maintenance		1,369			1,149	2,665		2,311
Operating and maintenance from affiliates		161			159	332		308
Depreciation and amortization		408			255	697		509
Taxes other than income		118			124	244		246
Total operating expenses		3,633			3,536	7,958		8,656
Gain (Loss) on Sale of Assets and Asset Impairment Charges		31			7	31		6
Operating income		(13)			703	402		1,424
Other income and (deductions)
Interest expense, net		(89)			(90)	(176)		(180)
Interest expense to affiliates		(10)			(9)	(20)		(21)
Other, net		117			(31)	210		62
Total other income and (deductions)		18			(130)	14		(139)
Income before income taxes		5			573	416		1,285
Income taxes		(31)			181	120		407
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions		(8)			(2)	(11)		(3)
Net income		28			390	285		875
Net income (loss) attributable to noncontrolling interests		36			(8)	(17)		34
Net (loss) income attributable to membership interest		(8)			398	302		841
Other comprehensive income (loss), net of income taxes
Unrealized (loss) gain on cash flow hedges		1			2	(4)		(3)
Unrealized loss on equity investments		(2)			0	(4)		0
Unrealized gain on marketable securities		1			1	0		1
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		0			3	6		(9)
Other comprehensive income		0			6	(2)	[2]	(11)	[2]
Comprehensive income		28			396	283		864
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		36			(8)	(17)		34
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		(8)			404	300		830
Commonwealth Edison Co [Member]
Operating revenues [Abstract]
Operating revenues		1,283			1,147	2,527		2,331
Operating revenues from affiliates		3			1	8		2
Revenues		1,286			1,148	2,535		2,333
Operating expenses
Cost of Purchased Power		326			269	668		586
Purchased power and fuel from affiliates		13			6	18		15
Operating and maintenance		318			337	623		670
Operating and maintenance from affiliates		50			47	113		92
Depreciation and amortization		190			177	379		352
Taxes other than income		65			69	141		146
Total operating expenses		962			905	1,942		1,861
Gain (Loss) on Sale of Assets and Asset Impairment Charges		0			0	5		0
Operating income		324			243	598		472
Other income and (deductions)
Interest expense, net		(88)			(78)	(170)		(158)
Interest expense to affiliates		(3)			(3)	(7)		(7)
Other, net		3			5	7		9
Total other income and (deductions)		(88)			(76)	(170)		(156)
Income before income taxes		236			167	428		316
Income taxes		91			68	168		127
Net income		145			99	260		189
Other comprehensive income (loss), net of income taxes
Comprehensive income		145			99	260		189
Baltimore Gas and Electric Company [Member]
Operating revenues [Abstract]
Gas Domestic Regulated Revenue		94			86	340		402
Operating revenues from affiliates		4			1	9		8
Electric Revenue		582			541	1,260		1,254
Revenues		680			628	1,609		1,664
Operating expenses
Utilities Operating Expense, Purchased Power		108			130	235		338
Purchased power and fuel from affiliates		133			96	304		233
Utilities Operating Expense, Fuel Used		20			13	95		155
Operating and maintenance		177			120	345		276
Operating and maintenance from affiliates		31			29	65		55
Depreciation and amortization		97			87	206		192
Taxes other than income		55			54	114		111
Total operating expenses		621			529	1,364		1,360
Operating income		59			99	245		304
Other income and (deductions)
Interest expense, net		(20)			(20)	(40)		(42)
Interest expense to affiliates		(4)			(4)	(8)		(8)
Other, net		5			4	11		8
Total other income and (deductions)		(19)			(20)	(37)		(42)
Income before income taxes		40			79	208		262
Income taxes		6			32	73		105
Net income		34			47	135		157
Preferred security dividends and redemption		3			3	6		6
Net income attributable to common shareholders		31			44	129		151
Other comprehensive income (loss), net of income taxes
Comprehensive income		34			47	135		157
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		3			3	6		6
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		31			44	129		151
Pepco Holdings LLC [Member] | Predecessor [Member]
Operating revenues [Abstract]
Gas Domestic Regulated Revenue				$ 57	25			111
Operating revenues from affiliates				0	0			0
Electric Revenue				1,096	1,094			2,362
Revenues				1,153	1,119			2,473
Operating expenses
Cost of Purchased Power				471	417			1,005
Purchased power and fuel from affiliates				0	0			0
Utilities Operating Expense, Fuel Used				26	12			62
Operating and maintenance				294	288			589
Operating and maintenance from affiliates				0	0			0
Depreciation and amortization				152	152			307
Taxes other than income				105	111			229
Total operating expenses				1,048	980			2,192
Operating income				105	139			281
Other income and (deductions)
Interest expense, net				(65)	(71)			(140)
Other, net				(4)	12			21
Total other income and (deductions)				(69)	(59)			(119)
Income before income taxes				36	80			162
Income taxes				17	27			56
Net income				19	53			106
Other comprehensive income (loss), net of income taxes
Actuarial loss reclassified to periodic benefit cost				1	3			4
Other comprehensive income				1	3			4
Comprehensive income				$ 20	56			110
Pepco Holdings LLC [Member] | Successor [Member]
Operating revenues [Abstract]
Gas Domestic Regulated Revenue		26	$ 28
Operating revenues from affiliates		10	23
Electric Revenue		1,030	1,120
Revenues		1,066	1,171
Operating expenses
Cost of Purchased Power		263	288
Purchased power and fuel from affiliates		144	155
Utilities Operating Expense, Fuel Used		9	11
Operating and maintenance		223	670
Operating and maintenance from affiliates		23	25
Depreciation and amortization		160	174
Taxes other than income		108	123
Total operating expenses		930	1,446
Operating income		136	(275)
Other income and (deductions)
Interest expense, net		(66)	(71)
Other, net		11	12
Total other income and (deductions)		(55)	(59)
Income before income taxes		81	(334)
Income taxes		29	(77)
Net income		52	(257)
Other comprehensive income (loss), net of income taxes
Actuarial loss reclassified to periodic benefit cost		0	0
Other comprehensive income		0	0
Comprehensive income		52	$ (257)
Potomac Electric Power Company [Member]
Gain (Loss) on Disposition of Assets		8				8
Operating revenues [Abstract]
Operating revenues from affiliates		1			1	3		2
Electric Revenue		508			503	1,058		1,047
Revenues		509			504	1,061		1,049
Operating expenses
Cost of Purchased Power		64			162	256		373
Purchased power and fuel from affiliates		88			0	95		0
Operating and maintenance		100			102	389		213
Operating and maintenance from affiliates		9			1	10		2
Depreciation and amortization		70			63	144		125
Taxes other than income		89			93	182		190
Total operating expenses		420			421	1,076		903
Operating income		97			83	(7)		146
Other income and (deductions)
Interest expense, net		(31)			(31)	(68)		(61)
Other, net		6			8	14		13
Total other income and (deductions)		(25)			(23)	(54)		(48)
Income before income taxes		72			60	(61)		98
Income taxes		23			18	(1)		30
Net income		49			42	(60)		68
Other comprehensive income (loss), net of income taxes
Comprehensive income		49			42	(60)		68
Delmarva Power and Light Company [Member]
Operating revenues [Abstract]
Gas Domestic Regulated Revenue		26			25	85		111
Operating revenues from affiliates		2			2	4		3
Electric Revenue		253			244	554		577
Revenues		281			271	643		691
Operating expenses
Utilities Operating Expense, Purchased Power		70			114	216		292
Purchased power and fuel from affiliates		43			0	47		0
Utilities Operating Expense, Fuel Used		9			11	35		58
Operating and maintenance		73			74	277		156
Operating and maintenance from affiliates		5			1	6		1
Depreciation and amortization		38			35	76		74
Taxes other than income		13			12	28		24
Total operating expenses		251			247	685		605
Operating income		30			24	(42)		86
Other income and (deductions)
Interest expense, net		(13)			(13)	(25)		(25)
Other, net		3			2	6		5
Total other income and (deductions)		(10)			(11)	(19)		(20)
Income before income taxes		20			13	(61)		66
Income taxes		8			5	(1)		26
Net income		12			8	(60)		40
Other comprehensive income (loss), net of income taxes
Comprehensive income		12			8	(60)		40
Atlantic City Electric Company [Member]
Gain (Loss) on Disposition of Assets		1				1
Operating revenues [Abstract]
Operating revenues from affiliates		1			1	2		2
Electric Revenue		269			284	559		616
Revenues		270			285	561		618
Operating expenses
Cost of Purchased Power		129			147	285		338
Purchased power and fuel from affiliates		12			0	13		0
Operating and maintenance		63			68	275		136
Operating and maintenance from affiliates		5			1	5		2
Depreciation and amortization		41			43	81		86
Taxes other than income		2			1	4		3
Total operating expenses		252			260	663		565
Operating income		19			25	(101)		53
Other income and (deductions)
Interest expense, net		(16)			(16)	(32)		(32)
Other, net		2			1	5		3
Total other income and (deductions)		(14)			(15)	(27)		(29)
Income before income taxes		5			10	(128)		24
Income taxes		2			4	(31)		9
Net income		3			6	(97)		15
Other comprehensive income (loss), net of income taxes
Comprehensive income		$ 3			$ 6	$ (97)		$ 15

[1] In January 2015, in connection with Generation's $750 million issuance of five-year Senior Unsecured Notes, Exelon terminated certain floating-to-fixed interest rate swaps. As the original forecasted transactions were a series of future interest payments over a ten year period, a portion of the anticipated interest payments were probable not to occur. As a result, $26 million of anticipated payments were reclassified from AOCI to Other, net in Exelon's Consolidated Statement of Operations and Comprehensive Income.

[2] All amounts are net of tax. Amounts in parenthesis represent a decrease in AOCI.