Merger and Acquisitions (Tables)

9 Months Ended

Sep. 30, 2013

Business Acquisition [Line Items]

Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]

								Estimated amortization expense
Description	Weighted Average Amortization (Years) (b)	Gross		Accumulated Amortization		Net		Remainder of 2013		2014		2015		2016		2017		2018 and Beyond
Unamortized energy contracts, net (a)	1.5	$	1,499	$	(1,299)	$	200	$	79	$	75	$	18	$	(31)	$	(21)	$	80
Trade name	10.0		243		(40)		203		6		24		24		24		24		101
Retail relationships	12.4		214		(31)		183		5		19		18		18		18		105
Total, net		$	1,956	$	(1,370)	$	586	$	90	$	118	$	60	$	11	$	21	$	286

• Includes the fair value of BGE's power and gas supply contracts of $32 million for which an offsetting regulatory asset was also recorded.
• Weighted average amortization period was calculated as of the date of acquisition.

Schedule of Restructuring and Related Costs [Text Block]

Three Months Ended September 30, 2012
Severance Benefits (a)		Exelon		Generation		ComEd (b)		PECO		BGE (c)
Severance charges	$	8	$	4	$	1	$	1	$	1
Stock compensation		3		2		1		0		0
Total severance benefits	$	11	$	6	$	2	$	1	$	1
Nine Months Ended September 30, 2012
Severance Benefits (a)		Exelon		Generation		ComEd (b)		PECO		BGE (c)
Severance charges	$	117	$	68	$	16	$	8	$	18
Stock compensation		6		4		1		0		0
Other charges (d)		7		4		1		0		1
Total severance benefits	$	130	$	76	$	18	$	8	$	19

_________________

• The amounts above include $0 million and $40 million at Generation, $2 million and $16 million at ComEd, $1 million and $8 million at PECO, and $1 million and $7 million at BGE, for amounts billed by BSC through intercompany allocations for the three and nine months ended September 30, 2012, respectively.
• ComEd established regulatory assetsof $2 million and $18 million for severance benefits costs for the three and nine months ended September 30, 2012, respectively. The majority of these costs are expected to be recovered over a five-year period.
• BGE established regulatory assets of $1 million and $19 millionfor severance benefits costs for the three and nine months endedSeptember 30, 2012, respectively. The majority of these costs are being recovered over a five-year period beginning in March 2013.

(d) Primarily includes life insurance, employer payroll taxes, educational assistance and outplacement services.

Schedule of Restructuring Reserve by Type of Cost [Table Text Block]

Nine Months Ended September 30, 2013
Severance liability		Exelon		Generation		ComEd		PECO		BGE
Balance at December 31, 2012	$	111	$	33	$	1	$	0	$	11
Severance charges (a)		5		1		0		0		0
Stock compensation		1		0		0		0		0
Payments		(52)		(20)		0		0		(4)
Balance at September 30, 2013	$	65	$	14	$	1	$	0	$	7

• Includes salary continuance and health and welfare severance benefits. Amounts represent ongoing severance plan benefits.

Business Acquisition, Pro Forma Information [Table Text Block]

		Three Months Ended September 30, 2012
		Generation		Exelon
Total Revenues	$	4,293	$	6,841
Net income attributable to Exelon		282		492
Basic Earnings Per Share		n.a.	$	0.58
Diluted Earnings Per Share		n.a.		0.57
		Nine Months Ended September 30, 2012
		Generation		Exelon
Total Revenues	$	12,753	$	20,084
Net income attributable to Exelon		805		1,439
Basic Earnings Per Share		n.a.	$	1.79
Diluted Earnings Per Share		n.a.		1.79

Schedule Of Business Acquisitions By Acquisition [Text Block]

Purchase Price Allocation, excluding amortization	Exelon		Generation
Current assets	$	4,936	$	3,638
Property, plant and equipment		9,342		4,054
Unamortized energy contracts		3,218		3,218
Other intangibles, trade name and retail relationships		457		457
Investment in affiliates		1,942		1,942
Pension and OPEB regulatory asset		740		0
Other assets		2,265		1,266
Total assets		22,900		14,575
Current liabilities		3,408		2,804
Unamortized energy contracts		1,722		1,512
Long-term debt, including current maturities		5,632		2,972
Noncontrolling interest		90		90
Deferred credits and other liabilities and preferred securities		4,683		1,933
Total liabilities, preferred securities and noncontrolling interest		15,535		9,311
Total purchase price	$	7,365	$	5,264