Debt and Credit Agreements Quarter-End (Tables)

12 Months Ended

Dec. 31, 2011

Debt Tables [Abstract]

Commercial paper and credit facility borrowings outstanding

	Maximum Program Size at December 31,				Outstanding Commercial Paper at December 31,				Average Interest Rate on Commercial Paper Borrowings for the Year Ended December 31,
Commercial Paper Issuer		2011 (a)		2010 (a)		2011		2010	2011	2010
Exelon Corporate	$	500	$	957	$	161	$	-	0.42%	-
Generation		5,600		4,834		-		-	0.48%	-
ComEd		1,000		1,000		-		-	0.71%	0.74%
PECO		600		574		-		-	-	-
Total	$	7,700	$	7,365	$	161	$	-

(a) Equals aggregate bank commitments under revolving and bilateral credit agreements. See discussion below and Credit Agreements table below for items affecting effective program size.