Fair Value of Financial Assets and Liabilities (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Tables [Line Items]

Fair value of financial liabilities recorded at the carrying amount

The following tables present the carrying amounts and fair values of the Registrants’ short-term liabilities, long-term debt, SNF obligation, and trust preferred securities (long-term debt to financing trusts or junior subordinated debentures) as of September 30, 2015 and December 31, 2014:

Exelon

	September 30, 2015
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	678	$	3	$	675	$	—	$	678
Long-term debt (including amounts due within one year)	25,438		1,004		24,181		1,335		26,520
Long-term debt to financing trusts	648		—		—		663		663
SNF obligation	1,021		—		820		—		820

	December 31, 2014
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	463	$	3	$	448	$	12	$	463
Long-term debt (including amounts due within one year)	21,164		1,208		20,417		1,311		22,936
Long-term debt to financing trusts	648		—		—		648		648
SNF obligation	1,021		—		833		—		833

Assets and liabilities measured and recorded at fair value on recurring basis

The following tables present assets and liabilities measured and recorded at fair value on Exelon's and Generation’s Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of September 30, 2015 and December 31, 2014:

	Generation								Exelon
As of September 30, 2015	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Cash equivalents(a)	$	225	$	—	$	—	$	225	$	6,545	$	—	$	—	$	6,545
Nuclear decommissioning trust fund investments
Cash equivalents	301		67		—		368		301		67		—		368
Equity
Domestic	2,274		1,829		—		4,103		2,274		1,829		—		4,103
Foreign	598		—		—		598		598		—		—		598
Equity funds subtotal	2,872		1,829		—		4,701		2,872		1,829		—		4,701
Fixed income
Corporate debt	—		1,831		245		2,076		—		1,831		245		2,076

	Generation								Exelon
As of September 30, 2015	Level 1		Level 2		Level 3		Total		Level 1			Level 2			Level 3			Total
U.S. Treasury and agencies	1,142		—		—		1,142		1,142			—			—			1,142
Foreign governments	—		77		—		77		—			77			—			77
State and municipal debt	—		407		—		407		—			407			—			407
Other	—		468		—		468		—		—	468		—	—		—	468
Fixed income subtotal	1,142		2,783		245		4,170		1,142			2,783			245			4,170
Middle market lending	—		—		423		423		—			—			423			423
Private equity	—		—		116		116		—			—			116			116
Real estate	—		—		30		30		—		—	—		—	30			30
Other	—		329		—		329		—			329			—			329
Nuclear decommissioning trust fund investments subtotal(b)	4,315		5,008		814		10,137		4,315			5,008			814			10,137
Pledged assets for Zion Station decommissioning
Cash equivalents	—		11		—		11		—			11			—			11
Equities	5		1		—		6		5			1			—			6
Fixed income
U.S. Treasury and agencies	5		2		—		7		5			2			—			7
Corporate debt	—		57		—		57		—			57			—			57
State and municipal debt	—		10		—		10		—			10			—			10
Other	—		1		—		1		—		—	1		—	—			1
Fixed income subtotal	5		70		—		75		5			70			—			75
Middle market lending	—		—		144		144		—			—			144			144
Pledged assets for Zion Station      decommissioning subtotal(c)	10		82		144		236		10			82			144			236
Rabbi trust investments in mutual funds(d)(e)	16		—		—		16		46			—			—			46
Commodity derivative assets
Economic hedges	1,625		2,561		2,144		6,330		1,625			2,561			2,144			6,330
Proprietary trading	85		140		38		263		85			140			38			263
Effect of netting and allocation of collateral(f)	(1,865	)	(2,037	)	(835	)	(4,737	)	(1,865	)		(2,037	)		(835	)		(4,737	)
Commodity derivative assets subtotal	(155	)	664		1,347		1,856		(155	)		664			1,347			1,856
Interest rate and foreign currency derivative         assets
Derivatives designated as hedging instruments	—		—		—		—		—			37			—			37
Economic hedges	—		21		—		21		—			21			—			21
Proprietary trading	14		3		—		17		14			3			—			17
Effect of netting and allocation of collateral	(8	)	(6	)	—		(14	)	(8	)		(6	)		—			(14	)
Interest rate and foreign currency derivative         assets subtotal	6		18		—		24		6			55			—			61
Other investments	—		—		32		32		—			—			32			32
Total assets	4,417		5,772		2,337		12,526		10,767			5,809			2,337			18,913

	Generation												Exelon
As of September 30, 2015	Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3			Total
Liabilities
Commodity derivative liabilities
Economic hedges	(2,120		)	(2,478		)	(1,209		)	(5,807		)	(2,120		)	(2,478		)	(1,452		)	(6,050		)
Proprietary trading	(79		)	(140		)	(44		)	(263		)	(79		)	(140		)	(44		)	(263		)
Effect of netting and allocation of collateral(f)	2,218			2,472			1,080			5,770			2,218			2,472			1,080			5,770
Commodity derivative liabilities subtotal	19			(146		)	(173		)	(300		)	19			(146		)	(416		)	(543		)
Interest rate and foreign currency derivative         liabilities
Derivatives designated as hedging instruments	—			(21		)	—			(21		)	—			(21		)	—			(21		)
Economic hedges	—			(6		)	—			(6		)	—			(6		)	—			(6		)
Proprietary trading	(15		)	—			—			(15		)	(15		)	—			—			(15		)
Effect of netting and allocation of collateral	15			6			—			21			15			6			—			21
Interest rate and foreign currency derivative         liabilities subtotal	—			(21		)	—			(21		)	—			(21		)	—			(21		)
Deferred compensation obligation	—			(29		)	—			(29		)	—			(95		)	—			(95		)
Total liabilities	19			(196		)	(173		)	(350		)	19			(262		)	(416		)	(659		)
Total net assets	$	4,436		$	5,576		$	2,164		$	12,176		$	10,786		$	5,547		$	1,921		$	18,254

	Generation								Exelon
As of December 31, 2014	Level 1		Level 2		Level 3		Total		Level 1			Level 2			Level 3		Total
Assets
Cash equivalents(a)	$	405	$	—	$	—	$	405	$	1,119		$	—		$	—	$	1,119
Nuclear decommissioning trust fund investments
Cash equivalents	208		37		—		245		208			37			—		245
Equity
Domestic	2,423		2,207		—		4,630		2,423			2,207			—		4,630
Foreign	612		—		—		612		612			—			—		612
Equity funds subtotal	3,035		2,207		—		5,242		3,035			2,207			—		5,242
Fixed income
Corporate debt	—		2,023		239		2,262		—			2,023			239		2,262
U.S. Treasury and agencies	996		—		—		996		996			—			—		996
Foreign governments	—		95		—		95		—			95			—		95
State and municipal debt	—		438		—		438		—			438			—		438
Other	—		511		—		511		—		—	511		—	—		511
Fixed income subtotal	996		3,067		239		4,302		996			3,067			239		4,302
Middle market lending	—		—		366		366		—			—			366		366
Private equity	—		—		83		83		—			—			83		83
Real estate	—		—		3		3		—		—	—		—	3		3
Other	—		301		—		301		—			301			—		301
Nuclear decommissioning trust fund investments subtotal(b)	4,239		5,612		691		10,542		4,239			5,612			691		10,542
Pledged assets for Zion Station      decommissioning
Cash equivalents	—		15		—		15		—			15			—		15
Equities	6		1		—		7		6			1			—		7
Fixed income
U.S. Treasury and agencies	5		3		—		8		5			3			—		8
Corporate debt	—		89		—		89		—			89			—		89
State and municipal debt	—		10		—		10		—			10			—		10
Other	—		3		—		3		—		—	3		—	—		3
Fixed income subtotal	5		105		—		110		5			105			—		110
Middle market lending	—		—		184		184		—			—			184		184

	Generation												Exelon
As of December 31, 2014	Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3			Total
Pledged assets for Zion Station     decommissioning subtotal(c)	11			121			184			316			11			121			184			316
Rabbi trust investments(d)
Cash equivalents	—			—			—			—			1			—			—			1
Mutual funds(e)	16			—			—			16			46			—			—			46
Rabbi trust investments subtotal	16			—			—			16			47			—			—			47
Commodity derivative assets
Economic hedges	1,667			3,465			1,681			6,813			1,667			3,465			1,681			6,813
Proprietary trading	201			284			27			512			201			284			27			512
Effect of netting and allocation of collateral(f)	(1,982		)	(2,757		)	(557		)	(5,296		)	(1,982		)	(2,757		)	(557		)	(5,296		)
Commodity derivative assets subtotal	(114		)	992			1,151			2,029			(114		)	992			1,151			2,029
Interest rate and foreign currency derivative     assets
Derivatives designated as hedging instruments	—			8			—			8			—			31			—			31
Economic hedges	—			12			—			12			—			13			—			13
Proprietary trading	18			9			—			27			18			9			—			27
Effect of netting and allocation of collateral	(17		)	(12		)	—			(29		)	(17		)	(31		)	—			(48		)
Interest rate and foreign currency derivative     assets subtotal	1			17			—			18			1			22			—			23
Other investments	—			—			3			3			2			—			3			5
Total assets	4,558			6,742			2,029			13,329			5,305			6,747			2,029			14,081
Liabilities
Commodity derivative liabilities
Economic hedges	(2,241		)	(3,458		)	(788		)	(6,487		)	(2,241		)	(3,458		)	(995		)	(6,694		)
Proprietary trading	(195		)	(295		)	(42		)	(532		)	(195		)	(295		)	(42		)	(532		)
Effect of netting and allocation of collateral(f)	2,416			3,557			729			6,702			2,416			3,557			729			6,702
Commodity derivative liabilities subtotal	(20		)	(196		)	(101		)	(317		)	(20		)	(196		)	(308		)	(524		)
Interest rate and foreign currency derivative     liabilities
Derivatives designated as hedging instruments	—			(12		)	—			(12		)	—			(41		)	—			(41		)
Economic hedges	—			(2		)	—			(2		)	—			(103		)	—			(103		)
Proprietary trading	(14		)	(9		)	—			(23		)	(14		)	(9		)	—			(23		)
Effect of netting and allocation of collateral	25			10			—			35			25			29			—			54
Interest rate and foreign currency derivative     liabilities subtotal	11			(13		)	—			(2		)	11			(124		)	—			(113		)
Deferred compensation obligation	—			(31		)	—			(31		)	—			(107		)	—			(107		)
Total liabilities	(9		)	(240		)	(101		)	(350		)	(9		)	(427		)	(308		)	(744		)
Total net assets	$	4,549		$	6,502		$	1,928		$	12,979		$	5,296		$	6,320		$	1,721		$	13,337

______________ 

(a) Excludes certain cash equivalents considered to be held-to-maturity and not reported at fair value.

(b) Excludes net liabilities of $(34) million and $(5) million at September 30, 2015 and December 31, 2014, respectively. These items consist of net receivables related to pending securities sales, interest and dividend receivables, and payables related to pending securities purchases.

(c) Excludes net assets of $1 million and $3 million at September 30, 2015 and December 31, 2014, respectively. These items consist of net receivables related to pending securities sales, interest and dividend receivables, and payables related to pending securities purchases.

(d) Excludes $34 million and $35 million of cash surrender value of life insurance investment at September 30, 2015 and December 31, 2014, respectively, at Exelon Consolidated. Excludes $12 million and $11 million and of cash surrender value of life insurance investment at September 30, 2015 and December 31, 2014, respectively, at Generation.

(e) The mutual funds held by the Rabbi trusts at Exelon include $45 million related to deferred compensation and $1 million related to Supplemental Executive Retirement Plan at September 30, 2015, and $45 million related to deferred compensation and $1 million related to Supplemental Executive Retirement Plan at December 31, 2014.

(f) Collateral posted to/(received from) counterparties totaled $353 million, $435 million and $245 million allocated to Level 1, Level 2 and Level 3 commodity mark-to-market derivatives, respectively, as of September 30, 2015. Collateral posted to/(received from) counterparties totaled $434 million, $800 million and $172 million allocated to Level 1, Level 2 and Level 3 commodity mark-to-market derivatives, respectively, as of December 31, 2014.

ComEd, PECO and BGE

The following tables present assets and liabilities measured and recorded at fair value on the utility Registrants' Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of September 30, 2015 and December 31, 2014:

	ComEd											PECO										BGE
As of September 30, 2015	Level 1		Level 2			Level 3			Total			Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Assets
Cash equivalents	$	—	$	—		$	—		$	—		$	4	$	—		$	—	$	4		$	68	$	—		$	—	$	68
Rabbi trust investments in mutual funds (a)	—		—			—			—			8		—			—		8			5		—			—		5
Total assets	—		—			—			—			12		—			—		12			73		—			—		73
Liabilities
Deferred compensation     obligation	—		(7		)	—			(7		)	—		(11		)	—		(11		)	—		(4		)	—		(4		)
Mark-to-market derivative     liabilities (b)	—		—			(243		)	(243		)	—		—			—		—			—		—			—		—
Total liabilities	—		(7		)	(243		)	(250		)	—		(11		)	—		(11		)	—		(4		)	—		(4		)
Total net assets (liabilities)	$	—	$	(7	)	$	(243	)	$	(250	)	$	12	$	(11	)	$	—	$	1		$	73	$	(4	)	$	—	$	69

	ComEd											PECO										BGE
As of December 31, 2014	Level 1		Level 2			Level 3			Total			Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Assets
Cash equivalents	$	25	$	—		$	—		$	25		$	12	$	—		$	—	$	12		$	103	$	—		$	—	$	103
Rabbi trust investments in mutual funds (a)	—		—			—			—			9		—			—		9			5		—			—		$	5
Total assets	25		—			—			25			21		—			—		21			108		—			—		108
Liabilities
Deferred compensation obligation	—		(8		)	—			(8		)	—		(15		)	—		(15		)	—		(5		)	—		(5		)
Mark-to-market derivative liabilities (b)	—		—			(207		)	(207		)	—		—			—		—			—		—			—		—
Total liabilities	—		(8		)	(207		)	(215		)	—		(15		)	—		(15		)	—		(5		)	—		(5		)
Total net assets (liabilities)	$	25	$	(8	)	$	(207	)	$	(190	)	$	21	$	(15	)	$	—	$	6		$	108	$	(5	)	$	—	$	103

______________ 

(a) At PECO, excludes $12 million and $14 million of the cash surrender value of life insurance investments at September 30, 2015 and December 31, 2014, respectively.

(b) The Level 3 balance includes the current and noncurrent liability of $22 million and $221 million at September 30, 2015, respectively, and $20 million and $187 million at December 31, 2014, respectively, related to floating-to-fixed energy swap contracts with unaffiliated suppliers.

Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis

The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis during the three and nine months ended September 30, 2015 and 2014:

	Generation															ComEd						Exelon
Three Months Ended September 30, 2015	Nuclear Decommissioning Trust Fund Investments			Pledged Assets for Zion Station Decommissioning			Mark-to-Market Derivatives				Other Investments		Total Generation			Mark-to-Market Derivatives (b)			Eliminated in Consolidation			Total
Balance as of June 30, 2015	$	786		$	156		$	1,021			$	30	$	1,993		$	(223	)	$	—		$	1,770
Total realized / unrealized gains (losses)
Included in net income	—			—			(48		)	(a)	—		(48		)	—			—			(48		)
Included in noncurrent payables to affiliates	5			—			—				—		5			—			(5		)	—
Included in payable for Zion Station decommissioning	—			1			—				—		1			—			—			1
Included in regulatory assets	—			—			—				—		—			(20		)	5			(15		)
Change in collateral	—			—			90				—		90			—			—			90
Purchases, sales, issuances and settlements
Purchases	40			5			50				2		97			—			—			97
Sales	—			(18		)	(5		)		—		(23		)	—			—			(23		)
Settlements	(17		)	—			—				—		(17		)	—			—			(17		)
Transfers into Level 3	—			—			69				—		69			—			—			69
Transfers out of Level 3	—			—			(3		)		—		(3		)	—			—			(3		)
Balance as of September 30, 2015	$	814		$	144		$	1,174			$	32	$	2,164		$	(243	)	$	—		$	1,921
The amount of total gains (losses) included in income attributed to the change in unrealized gains (losses) related to assets and liabilities held for the three months ended September 30, 2015	$	(1	)	$	—		$	181			$	—	$	180		$	—		$	—		$	180

	Generation															ComEd						Exelon
Nine Months Ended September 30, 2015	Nuclear Decommissioning Trust Fund Investments			Pledged Assets for Zion Station Decommissioning			Mark-to-Market Derivatives				Other Investments		Total Generation			Mark-to-Market Derivatives (b)			Eliminated in Consolidation			Total
Balance as of December 31, 2014	$	691		$	184		$	1,050			$	3	$	1,928		$	(207	)	$	—		$	1,721
Total realized / unrealized gains (losses)
Included in net income	4			—			(87		)	(a)	—		(83		)	—			—			(83		)
Included in noncurrent payables to affiliates	20			—			—				—		20			—			(20		)	—
Included in payable for Zion Station decommissioning	—			2			—				—		2			—			—			2
Included in regulatory assets	—			—			—				—		—			(36		)	20			(16		)
Change in collateral	—			—			72				—		72			—			—			72
Purchases, sales, issuances and settlements
Purchases	186			16			107				29		338			—			—			338
Sales	(8		)	(58		)	(10		)		—		(76		)	—			—			(76		)
Settlements	(83		)	—			—				—		(83		)	—			—			(83		)
Transfers into Level 3	4			—			80				—		84			—			—			84
Transfers out of Level 3	—			—			(38		)		—		(38		)	—			—			(38		)
Balance as of September 30, 2015	$	814		$	144		$	1,174			$	32	$	2,164		$	(243	)	$	—		$	1,921
The amount of total gains included in income attributed to the change in unrealized gains related to assets and liabilities held for the nine months ended September 30, 2015	$	4		$	—		$	536			$	—	$	540		$	—		$	—		$	540

______________ 

(a) Includes a reduction for the reclassification of $229 million and $623 million of realized gains due to the settlement of derivative contracts for the three and nine months ended September 30, 2015, respectively.

(b) Includes $19 million of decreases in fair value and a reduction for realized gains due to settlements of $1 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the three months ended September 30, 2015. Includes $44 million of decreases in fair value and an increase for realized losses due to settlements of $8 million for the nine months ended September 30, 2015.

	Generation															ComEd						Exelon
Three Months Ended September 30, 2014	Nuclear Decommissioning Trust Fund Investments			Pledged Assets for Zion Station Decommissioning			Mark-to-Market Derivatives			Other Investments			Total Generation			Mark-to-Market Derivatives(b)			Eliminated in Consolidation			Total
Balance as of June 30, 2014	$	592		$	133		$	242		$	10		$	977		$	(134	)	$	—		$	843
Total realized / unrealized gains (losses)
Included in net income	1			—			76		(a)	—			77			—			—			77
Included in noncurrent payables to affiliates	3			—			—			—			3			—			(3		)	—
Included in payable for Zion Station decommissioning	—			(2		)	—			—			(2		)	—			—			(2		)
Included in regulatory assets	—			—			—			—			—			(44		)	3			(41		)
Change in collateral	—			—			79			—			79			—			—			79
Purchases, sales, issuances and settlements
Purchases	83			53			12			—			148			—			—			148
Sales	(8		)	(18		)	—			(7		)	(33		)	—			—			(33		)
Settlements	(27		)	—			—			—			(27		)	—			—			(27		)
Transfers into Level 3	—			—			21			—			21			—			—			21
Transfers out of Level 3	—			—			1			—			1			—			—			1
Balance as of September 30, 2014	$	644		$	166		$	431		$	3		$	1,244		$	(178	)	$	—		$	1,066
The amount of total gains included in income attributed to the change in unrealized gains related to assets and liabilities held for the three months ended September 30, 2014	$	1		$	—		$	163		$	—		$	164		$	—		$	—		$	164

	Generation																ComEd						Exelon
Nine Months Ended September 30, 2014	Nuclear Decommissioning Trust Fund Investments			Pledged Assets for Zion Station Decommissioning			Mark-to-Market Derivatives				Other Investments			Total Generation			Mark-to- Market Derivatives(b)			Eliminated in Consolidation			Total
Balance as of December 31, 2013	$	350		$	112		$	465			$	15		$	942		$	(193	)	$	—		$	749
Total realized / unrealized gains (losses)
Included in net income	5			—			(284		)	(a)	—			(279		)	—			—			$	(279	)
Included in noncurrent payables to affiliates	14			—			—				—			14			—			(14		)	$	—
Included in payable for Zion Station decommissioning	—			2			—				—			2			—			—			$	2
Included in regulatory assets	—			—			—				—			—			15			14			$	29
Change in collateral	—			—			257				—			257			—			—			$	257
Purchases, sales, issuances and settlements
Purchases	331			95			27				2			455			—			—			$	455
Sales	(10		)	(43		)	(6		)		(7		)	(66		)	—			—			$	(66	)
Settlements	(46		)	—			—				—			(46		)	—			—			$	(46	)
Transfers into Level 3	—			—			(9		)		—			(9		)	—			—			$	(9	)
Transfers out of Level 3	—			—			(19		)		(7		)	(26		)	—			—			$	(26	)
Balance as of September 30, 2014	$	644		$	166		$	431			$	3		$	1,244		$	(178	)	$	—		$	1,066
The amount of total gains (losses) included in income attributed to the change in unrealized gains (losses) related to assets and liabilities held for the nine months ended September 30, 2014	$	3		$	—		$	(264	)		$	—		$	(261	)	$	—		$	—		$	(261	)

______________ 

(a) Includes a reduction for the reclassification of $87 million and $20 million of realized gains due to the settlement of derivative contracts for the three and nine months ended September 30, 2014.

(b) Includes $45 million of decreases in fair value and an increase for realized losses due to settlements of $1 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the three months ended September 30, 2014. Includes $19 million of increases in fair value and a reduction for realized gains due to settlements of $4 million for the nine months ended September 30, 2014.

Total realized and unrealized gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis

The following tables present the income statement classification of the total realized and unrealized gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis during the three and nine months ended September 30, 2015 and 2014:

	Generation									Exelon
	Operating Revenues			Purchased Power and Fuel			Other, net(a)			Operating Revenues			Purchased Power and Fuel			Other, net(a)
Total gains (losses) included in net income for the three months ended September 30, 2015	$	(4	)	$	(44	)	$	—		$	(4	)	$	(44	)	$	—
Total gains (losses) included in net income for the nine months ended September 30, 2015	(31		)	(56		)	4			(31		)	(56		)	4
Change in the unrealized gains (losses) relating to assets and liabilities held for the three months ended September 30, 2015	198			(17		)	(1		)	198			(17		)	(1		)
Change in the unrealized gains (losses) relating to assets and liabilities held for the nine months ended September 30, 2015	538			(2		)	4			538			(2		)	4

	Generation								Exelon
	Operating Revenues			Purchased Power and Fuel			Other, net(a)		Operating Revenues			Purchased Power and Fuel			Other, net(a)
Total gains (losses) included in net income for the three months ended September 30, 2014	$	70		$	6		$	1	$	70		$	6		$	1
Total gains (losses) included in net income for the nine months ended September 30, 2014	(260		)	(24		)	5		(260		)	(24		)	5
Change in the unrealized gains (losses) relating to assets and liabilities held for the three months ended September 30, 2014	142			21			1		142			21			1
Change in the unrealized gains (losses) relating to assets and liabilities held for the nine months ended September 30, 2014	(293		)	29			3		(293		)	29			3

______________ 

(a) Other, net activity consists of realized and unrealized gains (losses) included in income for the NDT funds held by Generation.

Exelon Generation Co L L C [Member]

Fair Value Tables [Line Items]

Fair value of financial liabilities recorded at the carrying amount

Generation

	September 30, 2015
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	21	$	—	$	21	$	—	$	21
Long-term debt (including amounts due within one year)	8,996		—		7,978		1,335		9,313
SNF obligation	1,021		—		820		—		820

	December 31, 2014
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	36	$	—	$	24	$	12	$	36
Long-term debt (including amounts due within one year)	8,266		—		7,511		1,311		8,822
SNF obligation	1,021		—		833		—		833

Commonwealth Edison Co [Member]

Fair Value Tables [Line Items]

Fair value of financial liabilities recorded at the carrying amount

ComEd

	September 30, 2015
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	604	$	—	$	604	$	—	$	604
Long-term debt (including amounts due within one year)	6,100		—		6,731		—		6,731
Long-term debt to financing trust	206		—		—		206		206

	December 31, 2014
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	304	$	—	$	304	$	—	$	304
Long-term debt (including amounts due within one year)	5,958		—		6,788		—		6,788
Long-term debt to financing trust	206		—		—		213		213

PECO Energy Co [Member]

Fair Value Tables [Line Items]

Fair value of financial liabilities recorded at the carrying amount

PECO

	September 30, 2015
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Long-term debt (including amounts due within one year)	$	2,246	$	—	$	2,472	$	—	$	2,472
Long-term debt to financing trusts	184		—		—		196		196

	December 31, 2014
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Long-term debt (including amounts due within one year)	$	2,246	$	—	$	2,537	$	—	$	2,537
Long-term debt to financing trusts	184		—		—		199		199

Baltimore Gas and Electric Company [Member]

Fair Value Tables [Line Items]

Fair value of financial liabilities recorded at the carrying amount

BGE

	September 30, 2015
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	53	$	3	$	50	$	—	$	53
Long-term debt (including amounts due within one year)	1,905		—		2,118		—		2,118
Long-term debt to financing trusts	258		—		—		261		261

	December 31, 2014
	Carrying Amount		Fair Value
			Level 1		Level 2		Level 3		Total
Short-term liabilities	$	123	$	3	$	120	$	—	$	123
Long-term debt (including amounts due within one year)	1,942		—		2,178		—		2,178
Long-term debt to financing trusts	258		—		—		236		236