Adjustment To Accrued Interest On Uncertain Tax Positions

Name:	pom_AdjustmentToAccruedInterestOnUncertainTaxPositions
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Income Recognized Related To Filed Amended Return Net Of Taxes

+ Details

Name:	pom_IncomeRecognizedRelatedToFiledAmendedReturnNetOfTaxes
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Income Tax Adjustment

+ Details

Name:	pom_IncomeTaxAdjustment
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

INCOME TAXES [TO BE UPDATED BY TAX] [Abstract]

+ Details

Name:	pom_IncomeTaxesToBeUpdatedByTaxAbstract
Namespace Prefix:	pom
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase Decrease in Tax Expenses

+ Details

Name:	pom_IncreaseDecreaseInTaxExpenses
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Increase Decrease to Net Income

+ Details

Name:	pom_IncreaseDecreaseToNetIncome
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Non- Recurring Tax Benefits

+ Details

Name:	pom_NonRecurringTaxBenefits
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Recognized State Apportionment Factor Benefits

+ Details

Name:	pom_RecognizedStateApportionmentFactorBenefits
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reversal Of Tax Benefits Previously Recorded Permanent Tax Benefits

+ Details

Name:	pom_ReversalOfTaxBenefitsPreviouslyRecordedPermanentTaxBenefits
Namespace Prefix:	pom
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The sum of the portions of deferred tax assets as of the balance sheet date for which, based on the weight of available evidence, it is more likely than not will not be realized through future reductions of tax-based income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 17
-Subparagraph e

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43-49

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 47

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Subparagraph 2
-Article 4

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The portion of the difference between total income tax expense (benefit) as reported in the Income Statement and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the disposition of assets in the period.

+ Details

Name:	us-gaap_IncomeTaxReconciliationDispositionOfAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

+ Details

Name:	us-gaap_IncomeTaxReconciliationTaxSettlementsDomestic
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of cash received during the period as refunds for the overpayment of taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 29

+ Details

Name:	us-gaap_ProceedsFromIncomeTaxRefunds
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the amount of interest expense accrued as of the date of the statement of financial position for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 48
-Paragraph 21
-Subparagraph c

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 48
-Paragraph 15

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	May 31, 2011	Jun. 30, 2011	Jun. 30, 2010	Mar. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income Taxes
Consolidated effective tax rates from continuing operations		36.20%	30.30%		35.90%	35.80%
Reversal of permanent tax benefits		$ 22			$ 22
Income tax adjustment			8
Income tax refunds received	5
Income recognized related to filed amended return, net of taxes	4
Reversal of accrued interest income		2			2
Adjustment to accrued interest on uncertain tax positions		6			6
Income tax settlement with IRS		17			17
Non-recurring tax benefits							16
Recognized state apportionment factor benefits							8
Valuation allowances on deferred tax assets							8
Increase in tax expenses				4
Decrease to net income				2
State tax benefit related to prior years' asset dispositions		$ 4			$ 4