Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Operating revenues [Abstract]
Total operating revenues	$ 6,141	$ 5,966	$ 12,223		$ 10,656
Operating expenses
Purchased power	2,419	2,606	5,400		4,371
Operating and maintenance	1,892	1,841	3,656		3,809
Depreciation and amortization	533	494	1,076		876
Taxes other than income	271	254	548		448
Total operating expenses	5,115	5,195	10,680		9,504
Gain (loss) on equity method investments	(21)	(57)	(30)		(79)
Operating income	1,005	714	1,513		1,073
Other income and deductions
Interest expense	(246)	(250)	(863)		(439)
Interest expense to affiliates, net	(6)	(6)	(13)		(12)
Other, net	(17)	(43)	155		152
Total other income and deductions	(269)	(299)	(721)		(299)
Income before income taxes	736	415	792		774
Income taxes	239	126	294		284
Net income	497	289	498		490
Net income (loss) attributable to noncontrolling interests and preferred security dividends	(7)	(3)	(12)		(4)
Net income on common stock	490	286	486		486
Pension and non-pension postretirement benefit plans:
Prior service benefit reclassified to periodic benefit cost	0	1	1		1
Actuarial loss reclassified to periodic cost	50	41	100		82
Transition obligation reclassified to periodic cost					2
Pension and non-pension postretirement benefit plans valuation adjustment	2	(3)	77		(11)
Deferred Compensation Unit Valuation Adjustment	10		10
Change in unrealized gain (loss) on cash-flow hedges	(65)	(156)	(123)		59
Change in unrealized income (loss) on equity investments	8	6	36		6
Change in unrealized income (loss) on foreign currency translation	(5)	(2)	(6)		(2)
Change in unrealized gain (loss) on marketable securities	0	(1)	(1)		0
Other comprehensive income (loss)		(114)	94	[1]	137
Comprehensive income	497	175	592		627
Average shares of common stock outstanding:
Basic	856	853	856		779
Diluted	860	856	859		781
Earnings per average common share - basic
Net income	$ 0.57	$ 0.34	$ 0.57		$ 0.62
Earnings per average common share - diluted
Net income	$ 0.57	$ 0.33	$ 0.57		$ 0.62
Dividends per common share	$ 0.31	$ 0.53	$ 0.84		$ 1.05
Exelon Generation Co L L C [Member]
Operating revenues [Abstract]
Operating revenues	3,718	3,345	6,859		5,718
Operating revenues from affiliates	352	420	744		790
Total operating revenues	4,070	3,765	7,603		6,508
Operating expenses
Purchased power and fuel	1,946	1,852	4,114		2,896
Operating and maintenance	1,041	990	2,007		2,029
Operating and maintenance from affiliate	148	188	295		327
Depreciation and amortization	210	204	424		357
Taxes other than income	101	90	194		164
Total operating expenses	3,446	3,324	7,034		5,773
Gain (loss) on equity method investments	(21)	(57)	(30)		(79)
Operating income	603	384	539		656
Other income and deductions
Interest expense	(93)	(85)	(176)		(138)
Other, net	(33)	(76)	95		103
Total other income and deductions	(126)	(161)	(81)		(35)
Income before income taxes	477	223	458		621
Income taxes	149	58	148		289
Net income	328	165	310		332
Income (Loss) attributable to noncontrolling interest	2	1	1		2
Net income on membership interest	330	166	311		334
Pension and non-pension postretirement benefit plans:
Change in unrealized gain (loss) on cash-flow hedges	(137)	(266)	(267)		(14)
Change in unrealized income (loss) on equity investments	8	6	36		6
Change in unrealized income (loss) on foreign currency translation	(5)	(2)	(6)		(2)
Change in unrealized gain (loss) on marketable securities		(1)	(1)		(1)
Other comprehensive income (loss)	(134)	(263)	(238)	[1]	(11)
Comprehensive income	194	(98)	72		321
Commonwealth Edison Co [Member]
Operating revenues [Abstract]
Operating revenues	1,080	1,280	2,238		2,669
Operating revenues from affiliates		1	1		1
Total operating revenues	1,080	1,281	2,239		2,670
Operating expenses
Purchased power	127	384	364		757
Purchased power from affiliate	121	203	266		451
Operating and maintenance	319	293	611		569
Operating and maintenance from affiliate	40	38	76		81
Depreciation and amortization	170	152	337		300
Taxes other than income	71	69	145		144
Total operating expenses	848	1,139	1,799		2,302
Operating income	232	142	440		368
Other income and deductions
Interest expense	(72)	(71)	(422)		(150)
Interest expense to affiliates, net	(4)	(3)	(7)		(6)
Other, net	6	3	11		7
Total other income and deductions	(70)	(71)	(418)		(149)
Income before income taxes	162	71	22		219
Income taxes	66	29	8		90
Net income	96	42	14		129
Pension and non-pension postretirement benefit plans:
Change in unrealized gain (loss) on marketable securities					1
Other comprehensive income (loss)					1
Comprehensive income	96	42	14		130
PECO Energy Co [Member]
Operating revenues [Abstract]
Operating revenues	672	714	1,567		1,588
Operating revenues from affiliates		1			2
Total operating revenues	672	715	1,567		1,590
Operating expenses
Purchased power	161	171	426		472
Purchased power from affiliate	97	125	238		235
Operating and maintenance	155	146	319		318
Operating and maintenance from affiliate	26	26	50		57
Depreciation and amortization	56	54	113		107
Taxes other than income	39	42	80		74
Total operating expenses	534	564	1,226		1,263
Operating income	138	151	341		327
Other income and deductions
Interest expense	(25)	(28)	(51)		(56)
Interest expense to affiliates, net	(3)	(3)	(6)		(6)
Other, net	0	2	3		5
Total other income and deductions	(28)	(29)	(54)		(57)
Income before income taxes	110	122	287		270
Income taxes	32	42	87		93
Net income	78	80	200		177
Preferred security dividends	(6)	(1)	(7)		(2)
Net income on common stock	72	79	193		175
Pension and non-pension postretirement benefit plans:
Change in unrealized gain (loss) on marketable securities					1
Other comprehensive income (loss)					1
Comprehensive income	78	80	200		178
Baltimore Gas and Electric Company [Member]
Operating revenues [Abstract]
Operating revenues	649	614	1,525		1,307
Operating revenues from affiliates	4	2	8		5
Total operating revenues	653	616	1,533		1,312
Operating expenses
Purchased power and fuel	189	201	501		494
Purchased power and fuel from affiliate	99	84	212		176
Operating and maintenance	139	136	266		297
Operating and maintenance from affiliate	21	25	37		59
Depreciation and amortization	82	71	175		150
Taxes other than income	54	47	109		95
Total operating expenses	584	564	1,300		1,271
Operating income	69	52	233		41
Other income and deductions
Interest expense	(32)	(34)	(66)		(75)
Other, net	4	7	9		13
Total other income and deductions	(28)	(27)	(57)		(62)
Income before income taxes	41	25	176		(21)
Income taxes	16	9	70		(7)
Net income	25	16	106		(14)
Preferred security dividends	(3)	(3)	(6)		(6)
Net income on common stock	22	13	100		(20)
Pension and non-pension postretirement benefit plans:
Comprehensive income	$ 25	$ 16	$ 106		$ (14)

[1] (a) All amounts are net of tax. Amounts in parenthesis represent a decrease in accumulated other comprehensive income.