Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2012

Dec. 31, 2011

Regulatory Matters Tables [Abstract]

Illinois Settlement Agreement contributions

		Generation		ComEd		Total Credits Issued to ComEd Customers
Year Ended December 31, 2010
Credits to ComEd customers(a)	$	14	$	1	$	15
Credits to other Illinois utilities’ customers(a)		7		n/a		n/a
Total incurred costs	$	21	$	1	$	15

(a)       Recorded as a reduction in operating revenues.

Regulatory assets and liabilities

December 31, 2012		Exelon				ComEd				PECO				BGE
Regulatory assets		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent
Pension and other postretirement
	benefits	$	304	$	3,673	$	0	$	0	$	0	$	0	$	0	$	0
Deferred income taxes			14		1,382		5		62		0		1,255		9		65
AMI programs			3		70		3		10		0		29		0		31
AMI meter events			0		17		0		0		0		17		0		0
Under-recovered distribution service
	costs		18		191		18		191		0		0		0		0
Debt costs			14		68		11		62		3		6		1		9
Fair value of BGE long-term debt (a)			0		256		0		0		0		0		0		0
Fair value of BGE supply contract (b)			77		12		0		0		0		0		0		0
Severance			29		28		25		12		0		0		4		16
Asset retirement obligations			0		90		0		65		0		25		0		0
MGP remediation costs			58		232		51		197		6		33		1		2
RTO start-up costs			3		2		3		2		0		0		0		0
Under-recovered electric universal
	service fund costs		11		0		0		0		11		0		0		0
Financial swap with Generation			0		0		226		0		0		0		0		0
Renewable energy and associated
	RECs		18		49		18		49		0		0		0		0
Under-recovered energy and
	transmission costs		43		0		14		0		1		0		28		0
DSP Program costs			1		3		0		0		1		3		0		0
DSP II Program costs			1		2		0		0		1		2		0		0
Deferred storm costs			3		6		0		0		0		0		3		6
Electric generation-related
	regulatory asset		16		40		0		0		0		0		16		40
Rate stabilization deferral			67		225		0		0		0		0		67		225
Energy efficiency and demand
	response programs		56		126		0		0		0		0		56		126
Other			23		25		14		16		9		8		0		2
Total regulatory assets		$	759		6,497	$	388	$	666	$	32	$	1,378	$	185	$	522

_________________

• Represents the regulatory asset recorded at Exelon Corporate for the difference in the fair value of the long-term debt of BGE as of the merger date. See Note 4 – Merger and Acquisitions for additional information.
• Represents the regulatory asset recorded at Exelon Corporate representing the fair value of BGE's supply contracts as of the merger date. BGE is allowed full recovery of the costs of its electric and gas supply contracts through approved regulated rates. See Note 4 – Merger and Acquisitions for additional information.

December 31, 2012		Exelon				ComEd				PECO				BGE
Regulatory liabilities		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent
Nuclear decommissioning		$	0	$	2,397	$	0	$	2,037	$	0	$	360	$	0	$	0
Removal costs			97		1,406		75		1,192		0		0		22		214
Energy efficiency and demand
	response programs		131		0		43		0		88		0		0		0
Electric distribution tax repairs			20		132		0		0		20		132		0		0
Gas distribution tax repairs			8		46						8		46
Over-recovered uncollectible
	accounts		6		0		6		0		0		0		0		0
Over-recovered energy and
	transmission costs		54		0		6		0		48		0		0		0
Over-recovered gas universal
	service fund costs		3		0		0		0		3		0		0		0
Over-recovered AEPS costs			2		0		0		0		2		0		0		0
Total regulatory liabilities		$	321	$	3,981	$	130	$	3,229	$	169	$	538	$	22	$	214

December 31, 2011		Exelon				ComEd				PECO				BGE
Regulatory assets		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent
Pension and other postretirement
	benefits	$	204	$	2,794	$	0	$	0	$	7	$	0	$	3	$	0
Deferred income taxes			5		1,176		5		66		0		1,110		8		68
AMI and smart meter programs			2		28		2		6		0		22		0		15
Under-recovered distribution service
	costs		14		70		14		70		0		0		0		0
Debt costs			18		81		15		73		3		8		2		10
Severance			25		38		25		38		0		0		0		1
Asset retirement obligations			0		74		0		50		0		24		0		0
MGP remediation costs			30		129		24		91		6		38		1		2
RTO start-up costs			3		4		3		4		0		0		0		0
Under-recovered electric universal
	service fund costs		3		0		0		0		3		0		0		0
Financial swap with Generation			0		0		503		191		0		0		0		0
Renewable energy and associated
	RECs		9		97		9		97		0		0		0		0
Under-recovered energy and
	transmission costs		57		0		48		0		9		0		50		0
DSP Program costs			3		2		0		0		3		2		0		0
Deferred storm costs			0		0		0		0		0		0		3		9
Electric generation-related
	regulatory asset		0		0		0		0		0		0		16		56
Rate stabilization deferral			0		0		0		0		0		0		63		295
Energy efficiency and demand
	response programs		0		0		0		0		0		0		29		95
Other			17		25		9		13		8		12		0		0
Total regulatory assets		$	390	$	4,518	$	657	$	699	$	39	$	1,216	$	175	$	551

December 31, 2011		Exelon				ComEd				PECO				BGE
Regulatory liabilities		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent		Current		Noncurrent
Nuclear decommissioning		$	0	$	2,222	$	0	$	1,857	$	0	$	365	$	0	$	0
Removal costs			61		1,185		61		1,185		0		0		18		200
Energy efficiency and demand
	response programs		49		69		49		0		0		69		0		0
Electric distribution tax repairs			19		151		0		0		19		151		0		0
Over-recovered uncollectible
	accounts		15		0		15		0		0		0		0		0
Over-recovered energy and
	transmission costs		42		0		12		0		30		0		0		0
Over-recovered gas universal
	service fund costs		3		0		0		0		3		0		0		0
Over-recovered AEPS costs			8		0		0		0		8		0		0		0
Other			0		0		0		0		0		0		1		1
Total regulatory liabilities		$	197	$	3,627	$	137	$	3,042	$	60	$	585	$	19	$	201

Regulatory Construction Commitment

		Total		2013		2014		2015		2016		2017
ComEd	$	525	$	175	$	86	$	135	$	128	$	1
PECO		140		28		23		26		36		27
BGE		249		15		53		119		55		7

Purchase Of Receivables [Table Text Block]

As of December 31, 2012	Exelon		ComEd		PECO		BGE
Purchased receivables (a)	$	191	$	55	$	65	$	71
Allowance for uncollectible accounts (b)		(21)		(9)		(6)		(6)
Purchased receivables, net	$	170	$	46	$	59	$	65
As of December 31, 2011	Exelon		ComEd		PECO		BGE
Purchased receivables (a)	$	68	$	16	$	52	$	61
Allowance for uncollectible accounts (b)		(5)		-		(5)		(3)
Purchased receivables, net	$	63	$	16	$	47	$	58