Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2012

Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member]

Variable Interest Entity [Line Items]

Schedule of Variable Interest Entities [Table Text Block]

		March 31, 2012
		Exelon		Generation		BGE
Current assets		$	525	$	474	$	50
Noncurrent assets			410		364		-
	Total assets	$	935	$	838	$	50
Current liabilities		$	415	$	340	$	74
Noncurrent liabilities			606		228		332
	Total liabilities	$	1,021	$	568	$	406

Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member]

Variable Interest Entity [Line Items]

Schedule of Variable Interest Entities [Table Text Block]

				Equity
		Energy		Method
		Contract		Investment
March 31, 2012		VIEs		VIEs		Total
Total assets (a)		$	286	$	350	$	636
Total liabilities (a)			223		113		336
Registrants' ownership interest (a)			0		94		94
Other ownership interests (a)			63		143		206
Registrants' maximum exposure to loss:
	Letters of credit		14		0		14
	Carrying amount of our equity method investments		0		76		76
	Debt and payment guarantees		0		5		5