Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2013

Retirement Benefits [Line Items]

Schedule of Defined Benefit Plans Disclosures [Text Block]

			Pension Benefits				Other Postretirement Benefits
			Three Months Ended				Three Months Ended
			June 30,				June 30,
			2013		2012		2013		2012
Service cost		$	79	$	74	$	40	$	39
Interest cost			163		179		49		54
Expected return on assets			(254)		(253)		(33)		(29)
Amortization of:
	Transition obligation		0		0		0		2
	Prior service cost (benefit)		4		3		(6)		(3)
	Actuarial loss		141		115		21		19
Contractual termination benefit cost (a)			0		14		0		6
Curtailment gain			0		0		0		(2)
Net periodic benefit cost		$	133	$	132	$	71	$	86
			Pension Benefits				Other Postretirement Benefits
			Six Months Ended				Six Months Ended
			June 30,				June 30,
			2013		2012		2013		2012
Service cost		$	159	$	135	$	81	$	76
Interest cost			326		343		97		104
Expected return on assets			(508)		(484)		(66)		(58)
Amortization of:
	Transition obligation		0		0		0		6
	Prior service cost (benefit)		7		7		(10)		(6)
	Actuarial loss		281		221		42		38
Contractual termination benefit cost (a)			0		14		0		6
Curtailment gain			0		0		0		(2)
Net periodic benefit cost		$	265	$	236	$	144	$	164

• ComEd and BGE established regulatory assets of $1 million and $4 million, respectively, for their portion of the second quarter 2012 contractual termination benefit charge.

Schedule Of Pension And Other Postretirement Benefit Costs [Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
Pension and Other Postretirement Benefit Costs	2013		2012		2013		2012
Generation	$	87	$	94	$	173	$	175
ComEd		77		68		154		137
PECO		10		13		21		26
BGE (a)(b)		14		18		27		32
BSC (c)		16		25		34		42

(b)       BGE's pension and other postretirement benefit costs for the three and six months ended June 30, 2012 includes a $3 million contractual termination benefit charge, which was recorded as a regulatory asset as of June 30, 2012.

Schedule Of Defined Contributions [Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
Savings Plan Matching Contributions	2013		2012		2013		2012
Exelon	$	21	$	19	$	43	$	35
Generation		10		8		21		16
ComEd		5		5		10		9
PECO		2		2		4		4
BGE (a)		2		1		4		3
BSC (b)		2		3		4		4

• BGE's matching contributions for the six months ended June 30, 2012 include $1 million of costs incurred prior to the closing of Exelon's merger with Constellation on March 12, 2012, which is not included in Exelon's matching contributions for the six months ended June 30, 2012.
• These amounts primarily represent amounts billed to Exelon's subsidiaries through intercompany allocations. These costs are not included in the Generation, ComEd, PECO or BGE amounts above.