Supplemental Financial Information (Tables)

3 Months Ended

Mar. 31, 2012

Supplemental Financial Information Tables [Line Items]

Components of depreciation, amortization and accretion, and other, net

Three Months Ended March 31, 2012	Exelon		Generation		ComEd		PECO		BGE
Depreciation, amortization, accretion and depletion
Property, plant and equipment	$	354	$	150	$	131	$	51	$	61
Regulatory assets		25		0		18		2		18
Amortization of intangible assets		3		3		0		0		0
Amortization of energy contract assets and liabilities (a)		131		131		0		0		0
Nuclear fuel(a)		207		207		0		0		0
Asset retirement obligation accretion(b)		56		56		0		0		0
Total depreciation, amortization and accretion	$	776	$	547	$	149	$	53	$	79
Three Months Ended March 31, 2011	Exelon		Generation		ComEd		PECO		BGE
Depreciation, amortization and accretion
Property, plant and equipment	$	313	$	139	$	122	$	46	$	57
Regulatory assets		14		0		12		2		20
Nuclear fuel(a)		174		174		0		0		0
Asset retirement obligation accretion(b)		51		51		0		0		0
Total depreciation, amortization and accretion	$	552	$	364	$	134	$	48	$	77

Components of non-operating income and expenses

Three Months Ended March 31, 2012			Exelon		Generation		ComEd		PECO		BGE
Other, Net
Decommissioning-related activities:
	Net realized income on decommissioning trust funds (a)
		Regulatory Agreement Units	$	60	$	60	$	0	$	0	$	0
		Non-Regulatory Agreement Units		48		48		0		0		0
	Net unrealized income on decommissioning trust funds
		Regulatory Agreement Units		247		247		0		0		0
		Non-Regulatory Agreement Units		65		65		0		0		0
	Net unrealized income on pledged assets
		Zion Station decommissioning		35		35		0		0		0
	Regulatory offset to decommissioning trust fund-related
		activities(b)		(277)		(277)		0		0		0
Total decommissioning-related activities				178		178		0		0		0
Investment income				4		0		1		1		3
Long-term lease income				7		0		0		0		0
AFUDC - Equity				3		0		1		1		3
Other				2		0		2		0		0
Other, net			$	194	$	178	$	4	$	2	$	6

Three Months Ended March 31, 2011			Exelon		Generation		ComEd		PECO		BGE
Other, Net
Decommissioning-related activities:
	Net realized income on decommissioning trust funds (a)
		Regulatory Agreement Units	$	43	$	43	$	0	$	0	$	0
		Non-Regulatory Agreement Units		10		10		0		0		0
	Net unrealized income on decommissioning trust funds
		Regulatory Agreement Units		111		111		0		0		0
		Non-Regulatory Agreement Units		43		43		0		0		0
	Net unrealized gains on pledged assets
		Zion Station decommissioning		23		23		0		0		0
	Regulatory offset to decommissioning trust fund-related
		activities (b)		(151)		(151)		0		0		0
Total decommissioning-related activities				79		79		0		0		0
Investment income				1		0		0		1		4
Long-term lease income				7		0		0		0		0
Interest income related to uncertain income tax provisions				3		0		1		0
AFUDC - Equity				5		0		1		4		4
Other				(1)		(4)		2		1
Other, net			$	94	$	75	$	4	$	6	$	8

Cash Flow Supplemental Disclosures

Three Months Ended March 31, 2012	Exelon		Generation		ComEd		PECO			BGE
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	$	181	$	81	$	69	$	13		$	16
Provision for uncollectible accounts		40		(9)		22		24			8
Stock-based compensation costs		39		0		0		0			0
Other decommissioning-related activity (a)		(71)		(71)		0		0			0
Energy-related options (b)		28		28		0		0			0
Amortization of regulatory asset related to debt costs		6		0		4		1			1
Amortization of rate stabilization deferral		3		0		0		0			13
Discrete impacts from EIMA (c)		(38)		0		(38)		0			0
Merger-related commitments (d)		331		35		0		0			141
Equity in loss of unconsolidated subsidiaries		22		22		0		0			0
Other		(11)		4		3		2			(1)
Total other non-cash operating activities	$	530	$	90	$	60	$	40		$	178
Changes in other assets and liabilities:
Under/over-recovered energy and transmission costs		(25)		0		(38)		13			(10)
Other regulatory assets and liabilities		(97)		0		(16)		3			(16)
Other current assets		(18)		(122)		1		(134)	(e)		31
Other noncurrent assets and liabilities		18		42		(19)		8			7
Total changes in other assets and liabilities	$	(122)	$	(80)	$	(72)	$	(110)		$	12
Non-cash investing and financing activities:
Merger with Constellation, common stock issued	$	7,365	$	5,272	$	0	$	0		$	0

Three Months Ended March 31, 2011	Exelon		Generation		ComEd		PECO			BGE
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	$	136	$	62	$	54	$	8		$	11
Provision for uncollectible accounts		45		0		19		26			9
Stock-based compensation costs		28		0		0		0			0
Other decommissioning-related activity (a)		(32)		(32)		0		0			0
Energy-related options (b)		34		34		0		0			0
Amortization of regulatory asset related to debt costs		6		0		5		1			1
Uncollectible accounts recovery, net		4		0		4		0			0
Amortization of rate stabilization deferral		0		0		0		0			14
Deferral of storm costs		0		0		0		0			(16)
Other		2		8		0		0			(3)
Total other non-cash operating activities	$	223	$	72	$	82	$	35		$	16
Changes in other assets and liabilities:
Under/over-recovered energy and transmission costs		(60)		0		(29)		(31)			3
Other regulatory assets and liabilities		3		0		5		(2)			(3)
Other current assets		(169)		(20)		(8)		(136)	(e)		31
Other noncurrent assets and liabilities		8		0		(3)		7			(5)
Total changes in other assets and liabilities	$	(218)	$	(20)	$	(35)	$	(162)		$	26

Supplemental Balance Sheet Disclosures

March 31, 2012	Exelon			Generation			ComEd		PECO		BGE
Property, plant and equipment:
Accumulated depreciation	$	11,244	(a)	$	5,563	(a)	$	2,769	$	2,691	$	2,508
Accounts receivable:
Allowance for uncollectible accounts		317			82			90		111		34
December 31, 2011	Exelon			Generation			ComEd		PECO		BGE
Property, plant and equipment:
Accumulated depreciation	$	10,959	(b)	$	5,313	(b)	$	2,750	$	2,662	$	2,465
Accounts receivable:
Allowance for uncollectible accounts		199			29			78		92		38

Accumulated Other Comprehensive Income Net Of Taxes

March 31, 2012	Exelon		Generation		ComEd		PECO		BGE
Accumulated other comprehensive income (loss)
Net unrealized gain on cash flow hedges	$	703	$	1,167	$	0	$	0	$	0
Pension and non-pension postretirement benefit plans		(2,904)		0		0		0		0
Unrealized gain on marketable securities		2		0		0		1		0
Total accumulated other comprehensive income (loss)	$	(2,199)	$	1,167	$	0	$	1	$	0
December 31, 2011	Exelon		Generation		ComEd		PECO		BGE
Accumulated other comprehensive income (loss)
Net unrealized gain on cash flow hedges	$	488	$	915	$	0	$	0	$	0
Pension and non-pension postretirement benefit plans		(2,938)		0		0		0		0
Unrealized loss on marketable securities		0		0		(1)		0		0
Total accumulated other comprehensive income (loss)	$	(2,450)	$	915	$	(1)	$	0	$	0