Fair Value Disclosures (Tables)

12 Months Ended

Dec. 31, 2011

Fair Value Disclosures [Abstract]

Fair Value Of Financial Assets And Liabilities Measured On A Recurring Basis

	Fair Value Measurements at December 31, 2011
Description	Total		Quoted Prices in Active Markets for Identical Instruments (Level 1) (a)		Significant Other Observable Inputs (Level 2) (a)		Significant Unobservable Inputs (Level 3)
	(millions of dollars)
ASSETS
Derivative instruments (b)
Electricity (c)	$	—	$	—	$	—	$	—
Cash equivalents
Treasury Fund		114		114		—		—
Executive deferred compensation plan assets
Money Market Funds		18		18		—		—
Life Insurance Contracts		60		—		43		17
	$	192	$	132	$	43	$	17
LIABILITIES
Derivative instruments (b)
Electricity (c)	$	32	$	—	$	32	$	—
Natural Gas (d)		67		50		—		17
Capacity		1		—		1		—
Executive deferred compensation plan liabilities
Life Insurance Contracts		28		—		28		—
	$	128	$	50	$	61	$	17

(a) There were no significant transfers of instruments between level 1 and level 2 valuation categories.

(b) The fair value of derivative assets and liabilities reflect netting by counterparty before the impact of collateral.

(c) Represents wholesale electricity futures and swaps that are used mainly as part of Pepco Energy Services' retail energy supply business.

(d) Level 1 instruments represent wholesale gas futures and swaps that are used mainly as part of Pepco Energy Services' retail energy supply business and level 3 instruments represent natural gas options purchased by DPL as part of a natural gas hedging program approved by the DPSC.

	Fair Value Measurements at December 31, 2010
Description	Total		Quoted Prices in Active Markets for Identical Instruments (Level 1)(a)		Significant Other Observable Inputs (Level 2)(a)		Significant Unobservable Inputs (Level 3)
	(millions of dollars)
ASSETS
Derivative instruments (b)
Electricity (c)	$	22	$	—	$	22	$	—
Cash equivalents
Treasury Fund		17		17		—		—
Executive deferred compensation plan assets
Money Market Funds		9		9		—		—
Life Insurance Contracts		66		—		47		19
	$	114	$	26	$	69	$	19
LIABILITIES
Derivative instruments (b)
Electricity (c)	$	88	$	—	$	88	$	—
Natural Gas (d)		98		75		—		23
Executive deferred compensation plan liabilities
Life Insurance Contracts		30		—		30		—
	$	216	$	75	$	118	$	23

(a) There were no significant transfers of instruments between level 1 and level 2 categories.

(b) The fair value of derivative assets and liabilities reflect netting by counterparty before the impact of collateral.

(c) Represents wholesale electricity futures and swaps that are used mainly as part of Pepco Energy Services' retail energy supply business.

(d) Level 1 instruments represent wholesale gas futures and swaps that are used mainly as part of Pepco Energy Services' retail energy supply business and level 3 instruments represent natural gas options purchased by DPL as part of a natural gas hedging program approved by the DPSC.

Reconciliations Of Fair Value Measurements Using Significant Unobservable Inputs (Level 3)

Year Ended December 31, 2011
	Natural Gas			Life Insurance Contracts
	(millions of dollars)
Beginning balance as of January 1, 2011	$	(23	)	$	19
Total gains (losses) (realized and unrealized):
Included in income		(4	)		6
Included in accumulated other comprehensive loss		—			—
Included in regulatory liabilities		(10	)		—
Purchases		—			—
Issuances		—			(3	)
Settlements		19			(5	)
Transfers in (out) of Level 3		1			—
Ending balance as of December 31, 2011	$	(17	)	$	17

	Year Ended December 31, 2010
	Natural Gas			Life Insurance Contracts
	(millions of dollars)
Beginning balance as of January 1, 2010	$	(29	)	$	19
Total gains (losses) (realized and unrealized):
Included in income		—			3
Included in accumulated other comprehensive loss		—			—
Included in regulatory liabilities		(20	)		—
Purchases		—			—
Issuances		—			(3	)
Settlements		26			—
Transfers in (out) of Level 3		—			—
Ending balance as of December 31, 2010	$	(23	)	$	19

Gains Or (Losses) On Level 3 Instruments Included In Income

	Year Ended December 31,
	2011		2010
	(millions of dollars)
Total net gains included in income for the period	$	2	$	3
Change in unrealized gains relating to assets still held at reporting date	$	2	$	3

Estimated Fair Values Of Debt And Equity Instruments

	December 31, 2011				December 31, 2010
	(millions of dollars)
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-Term Debt	$	3,867	$	4,577	$	3,665	$	4,045
Transition Bonds issued by ACE Funding		332		380		367		406
Long-Term Project Funding		15		15		19		19
Redeemable Serial Preferred Stock		—		—		6		5