XML 61 R72.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Regulatory Assets and Liabilities Regulatory Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2011 | Dec. 31, 2010
--- | --- | ---
Regulatory Assets and Liabilities Disclosure [Abstract] |  |
Regulatory Assets Earning a Return, Other Category | $ 21 | $ 26
Regulatory Assets Earning a Return | 22 |
Regulatory Assets Earning a Rate of Return at the Cost of Capital | 7 |
Authorized Cost of Capital | 8.033% |
Regulatory Assets Earning a Rate of Return at the Approved Rate | 7 |
Approved Rate for Deferred Account Under Amortization, Low End of Range | 2.01% |
Approved Rate for Deferred Accounts under Amortization, High End of Range | 4.27% |
Regulatory Assets Earning a Rate of Return by Inclusion in Rate Base | 8 |
Amount of Impairment to Carrying Amount of Regulatory Assets | $ 3 |

X
- Definition High end of the range of approved rates of return for amortizing deferred accounts (regulatory assets). + References No definition available. + Details
Name: | por_ApprovedRateForDeferredAccountsUnderAmortizationHighEndOfRange
Namespace Prefix: | por_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Low end of the range of approved rates of return for amortizing deferred accounts (regulatory assets). + References No definition available. + Details
Name: | por_ApprovedRateForDeferredAccountUnderAmortizationLowEndOfRange
Namespace Prefix: | por_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Authorized cost of capital rate. + References No definition available. + Details
Name: | por_AuthorizedCostOfCapital
Namespace Prefix: | por_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Regulatory assets earning a rate of return at the approved rate. + References No definition available. + Details
Name: | por_RegulatoryAssetsEarningRateOfReturnAtApprovedRate
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Regulatory assets earning a rate of return at the cost of capital. + References No definition available. + Details
Name: | por_RegulatoryAssetsEarningRateOfReturnAtCostOfCapital
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Regulatory assets earning a rate of return by inclusion in rate base. + References No definition available. + Details
Name: | por_RegulatoryAssetsEarningRateOfReturnByInclusionInRateBase
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Regulatory assets earning a rate of return. + References No definition available. + Details
Name: | por_RegulatoryAssetsEarningReturn
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Regulatory assets in 'other' category earning a rate of return. + References No definition available. + Details
Name: | por_RegulatoryAssetsEarningReturnOtherCategory
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Discloses the amount of any reduction to the carrying amounts of regulated assets that result from impairment (for example, rate actions of a regulator). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6066304&loc=d3e44026-110379 + Details
Name: | us-gaap_AmountOfImpairmentToCarryingAmountOfRegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryAssetsAndLiabilitiesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration