Derivative Instruments And Hedging Activities (Tables)

3 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2011

Jun. 30, 2011

Dec. 31, 2010

Fair Value Of Derivative Instruments By Balance Sheet Location

	As of June 30, 2011
Balance Sheet Caption	Derivatives Designated as Hedging Instruments			Other Derivative Instruments			Gross Derivative Instruments			Effects of Cash Collateral and Netting			Net Derivative Instruments
	(millions of dollars)
Derivative Assets (current assets)	$	30		$	20		$	50		$	(28	)	$	22
Derivative Assets (non-current assets)		—			2			2			(2	)		—
Total Derivative Assets		30			22			52			(30	)		22
Derivative Liabilities (current liabilities)		(92	)		(38	)		(130	)		83			(47	)
Derivative Liabilities (non-current liabilities)		(24	)		(10	)		(34	)		25			(9	)
Total Derivative Liabilities		(116	)		(48	)		(164	)		108			(56	)
Net Derivative (Liability) Asset	$	(86	)	$	(26	)	$	(112	)	$	78		$	(34	)

	As of December 31, 2010
Balance Sheet Caption	Derivatives Designated as Hedging Instruments			Other Derivative Instruments			Gross Derivative Instruments			Effects of Cash Collateral and Netting			Net Derivative Instruments
	(millions of dollars)
Derivative Assets (current assets)	$	40		$	43		$	83		$	(38	)	$	45
Derivative Assets (non-current assets)		16			3			19			(19	)		—
Total Derivative Assets		56			46			102			(57	)		45
Derivative Liabilities (current liabilities)		(125	)		(63	)		(188	)		122			(66	)
Derivative Liabilities (non-current liabilities)		(68	)		(10	)		(78	)		57			(21	)
Total Derivative Liabilities		(193	)		(73	)		(266	)		179			(87	)
Net Derivative (Liability) Asset	$	(137	)	$	(27	)	$	(164	)	$	122		$	(42	)

Schedule Of Cash Collateral Offset Against Derivative Positions

	June  30, 2011		December 31, 2010
	(millions of dollars)
Cash collateral pledged to counterparties with the right to reclaim (a)	$	78	$	122

(a) Includes cash deposits on commodity brokerage accounts

Cash Flow Hedges Related To Effective Portion Of Gain Or Loss On Derivatives

	Three Months Ended June  30,					Six Months Ended June  30,
	2011		2010			2011		2010
	(millions of dollars)
Amount of net pre-tax gain (loss) arising during the period included in accumulated other comprehensive loss	$	3	$	12		$	2	$	(78	)
Amount of net pre-tax loss reclassified into income:
Effective portion:
Fuel and Purchased Energy		19		39			46		85
Ineffective portion: (a) (b)
Revenue		—		(1	)		—		2
Total net pre-tax loss reclassified into income		19		38			46		87
Net pre-tax gain on commodity derivatives included in accumulated other comprehensive loss	$	22	$	50		$	48	$	9

(a) For the three months ended June 30, 2011 and 2010, amounts of zero and less than $1 million, respectively, were reclassified from AOCL to income because the forecasted hedged transactions were deemed probable not to occur.

(b) For the six months ended June 30, 2011 and 2010, amounts of zero and less than $1 million, respectively, were reclassified from AOCL to income because the forecasted hedged transactions were deemed probable not to occur.

Energy Commodity Contracts Employed As Cash Flow Hedges

	Quantities
Commodity	June 30, 2011		December 31, 2010
Forecasted Purchases Hedges
Natural gas (One Million British Thermal Units (MMBtu))		—		8,597,106
Electricity (Megawatt hours (MWh))		2,417,760		2,677,640
Electricity Capacity (MW-Days)		—		34,730
Forecasted Sales Hedges
Electricity (MWh)		1,356,480		2,517,200

Deferred Regulatory Assets Or Liabilities Reclassified To Income

	Three Months  Ended June 30,						Six Months  Ended June 30,
	2011			2010			2011			2010
	(millions of dollars)						(millions of dollars)
Net Unrealized Gain Deferred as a Regulatory Liability (Asset)	$	2		$	5		$	3		$	—
Net Realized Loss Recognized in Fuel and Purchased Energy Expense		(1	)		(3	)		(3	)		(5	)

Outstanding Commodity Forward Contracts Entered Into To Hedge Forecasted Transactions

	Quantities
Commodity	June 30, 2011		December 31, 2010
Forecasted Purchases Hedges
Natural Gas (MMBtu)		765,000		1,670,000

Cash Flow Hedges Included In Accumulated Other Comprehensive Loss

	As of June 30, 2011				Maximum Term
Contracts	Accumulated Other Comprehensive Loss After-tax (a)		Portion Expected to be Reclassified to Income during the Next 12 Months
	(millions of dollars)
Energy Commodity (b)	$	49	$	35	35 months
Interest Rate		11		1	254 months
Total	$	60	$	36

(a) AOCL on PHI's Consolidated Balance Sheet as of June 30, 2011, includes a $20 million balance related to minimum pension liability. This balance is not included in this table as the minimum pension liability is not a cash flow hedge.

(b) The unrealized derivative losses recorded in AOCL are largely offset by forecasted natural gas and electricity physical purchases for delivery to retail customers that are in gain positions and subject to accrual accounting. These forward purchase contracts are exempted from mark-to-market accounting because they either qualify as normal purchases under FASB guidance on derivatives and hedging or they are not derivative contracts. Under accrual accounting, no asset is recorded on the balance sheet for these contracts, and the purchase cost is not recognized until the period of distribution. Although Pepco Energy Services no longer designates its natural gas derivatives as cash flow hedges effective January 1, 2011, gains or losses previously deferred in AOCL as of December 31, 2010 would remain in AOCL unless it is probable that the hedged forecasted transaction will not occur. At June 30, 2011, the amount remaining in AOCL associated with natural gas derivatives was $41 million.

	As of June 30, 2010				Maximum Term
Contracts	Accumulated Other Comprehensive Loss After-tax (a)		Portion Expected to be Reclassified to Income during the Next 12 Months
	(millions of dollars)
Energy Commodity (b)	$	94	$	55	47 months
Interest Rate		20		3	266 months
Total	$	114	$	58

(a) AOCL on PHI's Consolidated Balance Sheet as of June 30, 2010, includes a $15 million balance related to minimum pension liability and a $32 million balance related to Conectiv Energy. These balances are not included in this table as the minimum pension liability is not a cash flow hedge and Conectiv Energy is reported as a discontinued operation.

(b) The unrealized derivative losses recorded in AOCL are largely offset by forecasted natural gas and electricity physical purchases for delivery to retail customers that are in gain positions and subject to accrual accounting. These forward purchase contracts are exempted from mark-to-market accounting because they either qualify as normal purchases under FASB guidance on derivatives and hedging or they are not derivative contracts. Under accrual accounting, no asset is recorded on the balance sheet for these contracts, and the purchase cost is not recognized until the period of distribution.

Amount Of Derivative Gain Or Loss Recognized In Income

	Three Months Ended June 30, 2011								Three Months Ended June 30, 2010
	Revenue			Fuel and Purchased Energy Expense		Total			Revenue		Fuel and Purchased Energy Expense		Total
	(millions of dollars)
Realized mark-to-market gains (losses)	$	2		$	—	$	2		$	1	$	—	$	1
Unrealized mark-to-market gains (losses)		(5	)		—		(5	)		—		—		—
Total net mark-to-market gains (losses)	$	(3	)	$	—	$	(3	)	$	1	$	—	$	1

	Six Months Ended June 30, 2011								Six Months Ended June 30, 2010
	Revenue			Fuel and Purchased Energy Expense		Total			Revenue		Fuel and Purchased Energy Expense		Total
	(millions of dollars)
Realized mark-to-market gains (losses)	$	(2	)	$	—	$	(2	)	$	1	$	—	$	1
Unrealized mark-to-market gains (losses)		(5	)		—		(5	)		—		—		—
Total net mark-to-market gains (losses)	$	(7	)	$	—	$	(7	)	$	1	$	—	$	1

Amount Of Derivative Loss Recognized In The Consolidated Statements Of Income

	Three Months Ended June  30,						Six Months Ended June  30,
	2011			2010			2011			2010
	(millions of dollars)
Net Unrealized Gain (Loss) Deferred as a Regulatory Liability (Asset)	$	2		$	7		$	9		$	1
Net Realized Loss Recognized in Fuel and Purchased Energy Expense		(4	)		(6	)		(11	)		(13	)

Pepco Energy Services [Member]

Net Outstanding Commodity Forward Contracts Not Qualified For Hedge Accounting

	June 30, 2011			December 31, 2010
Commodity	Quantity		Net Position	Quantity		Net Position
Financial transmission rights (MWh)		619,226	Long		381,215	Long
Electric Capacity (MW–Days)		28,560	Long		2,265	Short
Electric (MWh)		1,106,232	Long		1,455,800	Short
Natural gas (MMBtu)		36,003,000	Long		45,889,486	Short

Delmarva Power & Light Co/De [Member]

Net Outstanding Commodity Forward Contracts Not Qualified For Hedge Accounting

	June 30, 2011			December 31, 2010
Commodity	Quantity		Net Position	Quantity		Net Position
Natural Gas (MMBtu)		5,892,432	Long		7,827,635	Long