Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Significant Accounting Policies Tables [Abstract]

Schedule Of Capitalized Software [Text Block]

Net unamortized software costs	Exelon		Generation		ComEd		PECO		BGE
December 31, 2012	$	499	$	143	$	105	$	63	$	157
December 31, 2011		280		82		120		67		62
Amortization of capitalized software costs	Exelon (a)		Generation (a)		ComEd		PECO		BGE (a)
2012	$	208	$	81	$	56	$	30	$	32
2011		122		41		50		25		25
2010		104		33		41		19		26

Exelon activity for the year ended December 31, 2012 includes the results of Constellation and BGE for March 12, 2012 – December 31, 2012. Generation activity for the year ended December 31, 2012 includes the results of Constellation for March 12, 2012 – December 31, 2012. BGE activity represents the activity for the years ended December 31, 2012, 2011 and 2010

Schedule Of Capitalized Interest And AFUDC [Text Block]

		Exelon (a)		Generation (a)		ComEd		PECO		BGE (a)
2012	Total incurred interest (b)	$	1,003	$	368	$	310	$	125	$	149
	Capitalized interest		67		67		—		—		—
	Credits to AFUDC debt and equity		25		—		9		6		15
2011	Total incurred interest (b)	$	783	$	219	$	349	$	138	$	136
	Capitalized interest		49		49		—		—		—
	Credits to AFUDC debt and equity		25		—		12		13		22
2010	Total incurred interest (b)	$	861	$	191	$	388	$	197	$	137
	Capitalized interest		38		38		—		—		—
	Credits to AFUDC debt and equity		16		—		5		11		16

__________

(a)       Exelon activity for the year ended December 31, 2012 includes the results of Constellation and BGE for March 12, 2012 – December 31, 2012. Generation activity for the year ended December 31, 2012 includes the results of Constellation for March 12, 2012 – December 31, 2012. BGE activity represents the activity for the years ended December 31, 2012, 2011 and 2010.

(b)       Includes interest expense to affiliates.