2.4.0.8010002 - Document - Oppenheimer Rochester North Carolina Municipal Fund {Unlabeled}falsefalsetrue1false falsefalsec_S000012508_AAAAhttp://www.sec.gov/CIK0001357430duration2013-07-29T00:00:002013-07-29T00:00:001false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00(Oppenheimer Rochester North Carolina Municipal Fund)falsefalsefalse1false truefalsec_S000012508_AAAAhttp://www.sec.gov/CIK0001357430duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMembernanafalse0(Oppenheimer Rochester North Carolina Municipal Fund)2false 2rr_ObjectivePrimaryTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Investment Objective. The Fund seeks a high level of current interest income exempt from federal and North Carolina state income taxes for individual investors as is consistent with preservation of capital. falsefalsefalsenonnum:textBlockItemTypenaInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a false0Objective, Primary [Text Block]3false 2rr_ExpenseNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Fees and Expenses of the Fund. This table describes the fees and expenses that you may pay if you buy and hold or redeem shares of the Fund. You may qualify for sales charge discounts if you (or you and your spouse) invest, or agree to invest in the future, at least $50,000 in certain funds in the Oppenheimer family of funds. More information about these and other discounts is available from your financial professional and in the section "About Your Account" beginning on page 17 of the prospectus and in the sections "How to Buy Shares" beginning on page 79 and "Appendix A" in the Fund's Statement of Additional Information. falsefalsefalsenonnum:textBlockItemTypenaThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown. The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 1 -Subparagraph b false0Expense Narrative [Text Block]4false 2rr_ShareholderFeesCaptionrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Shareholder Fees (fees paid directly from your investment) falsefalsefalsexbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 false0Shareholder Fees Caption [Text]5false 2rr_ShareholderFeesTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~http://ofirchncmuni-20130729/role/ShareholderFeesDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsefalse<div style="display:none">~http://ofirchncmuni-20130729/role/ShareholderFeesDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsehttp://ofirchncmuni-20130729/role/ShareholderFeesDataAAAA020012 - Schedule - Shareholder Feestruefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseClass Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_C000034012Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalsedei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberClass ARatioStandardhttp://www.xbrl.org/2003/instancepurexbrli0Standard0 USDfalsefalseduration2013-07-29T00:00:002013-07-29T00:00:00$2falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseClass Brr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_C000034013Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalsedei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberClass BRatioStandardhttp://www.xbrl.org/2003/instancepurexbrli0Standard0 USDfalsefalseduration2013-07-29T00:00:002013-07-29T00:00:00$3falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseClass Crr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_C000034014Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalsedei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberClass CRatioStandardhttp://www.xbrl.org/2003/instancepurexbrli0Standard0 USDfalsefalseduration2013-07-29T00:00:002013-07-29T00:00:00$4falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseClass Yrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_C000102772Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalsedei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberClass YRatioStandardhttp://www.xbrl.org/2003/instancepurexbrli0Standard0 USDfalsefalseduration2013-07-29T00:00:002013-07-29T00:00:00$1falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member3false 2rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricerr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 1 false0Maximum Sales Charge (Load) imposed on purchases (as % of offering price)falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricerr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.04750.0475falsefalsefalse2truetruetrue00falsefalsefalse3truetruetrue00falsefalsefalse4truetruetrue00falsefalsefalserr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 1 false0Maximum Sales Charge (Load) imposed on purchases (as % of offering price)2falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member4false 2rr_MaximumDeferredSalesChargeOverOtherrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 2 -Subparagraph a -Clause i false0Maximum Deferred Sales Charge (Load) (as % of the lower of the original offering price or redemption proceeds)falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_MaximumDeferredSalesChargeOverOtherrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue00falsefalsefalse2truetruetrue0.050.05falsefalsefalse3truetruetrue0.010.01falsefalsefalse4truetruetrue00falsefalsefalserr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 2 -Subparagraph a -Clause i false0Maximum Deferred Sales Charge (Load) (as % of the lower of the original offering price or redemption proceeds)falseShareholder Fees (Oppenheimer Rochester North Carolina Municipal Fund)UnKnownUnKnownUnKnownUnKnownfalsefalsefalseSheet426442029ColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Memberfalsenonnum:textBlockItemTypenaContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No definition available.false0Shareholder Fees [Table]6false 2rr_OperatingExpensesCaptionrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment): [1]falsefalsefalsexbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 7 false0Operating Expenses Caption [Text]7false 2rr_AnnualFundOperatingExpensesTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://ofirchncmuni-20130729/role/OperatingExpensesDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsefalse<div style="display:none">~ http://ofirchncmuni-20130729/role/OperatingExpensesDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsehttp://ofirchncmuni-20130729/role/OperatingExpensesDataAAAA020022 - 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 9 false0Distribution and/or Service (12b-1) Feesfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_DistributionAndService12b1FeesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00240.0024falsefalsefalse2truetruetrue0.010.01falsefalsefalse3truetruetrue0.010.01falsefalsefalse4truetruetrue00falsefalsefalserr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 9 false0Distribution and/or Service (12b-1) Fees3falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member5false 2rr_Component1OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause iii false0Interest and Fees from Borrowingfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_Component1OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00080.0008falsefalsefalse2truetruetrue0.00080.0008falsefalsefalse3truetruetrue0.00080.0008falsefalsefalse4truetruetrue0.00080.0008falsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause iii false0Interest and Fees from Borrowing4falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member6false 2rr_Component2OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 10 false0Interest and Related Expenses from Inverse Floatersfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_Component2OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00050.0005falsefalsefalse2truetruetrue0.00050.0005falsefalsefalse3truetruetrue0.00050.0005falsefalsefalse4truetruetrue0.00050.0005falsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 10 false0Interest and Related Expenses from Inverse Floaters5falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member7false 2rr_Component3OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause iii false0Other Expensesfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_Component3OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00140.0014falsefalsefalse2truetruetrue0.00140.0014falsefalsefalse3truetruetrue0.00140.0014falsefalsefalse4truetruetrue0.00140.0014falsefalsefalserr:NonNegativePure4TypepureThe Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising "Other Expenses," but must include a total of all "Other Expenses." Alternatively, the Fund may include the components of "Other Expenses" in a parenthetical to the caption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause iii false0Other Expenses6falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member8false 2rr_OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabelrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause i true0Other Expensesfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truetruetrue0.00270.0027falsefalsefalse2truetruetrue0.00270.0027falsefalsefalse3truetruetrue0.00270.0027falsefalsefalse4truetruetrue0.00270.0027falsefalsefalserr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause i true0Other Expenses7falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member9false 2rr_ExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabelrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph d true0Total Expensesfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_ExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truetruetrue0.01060.0106falsefalsefalse2truetruetrue0.01820.0182falsefalsefalse3truetruetrue0.01820.0182falsefalsefalse4truetruetrue0.00820.0082falsefalsefalserr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph d true0Total Expenses8falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member10false 2rr_FeeWaiverOrReimbursementOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalserr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 false0Fee Waiver and/or Expense Reimbursementfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_FeeWaiverOrReimbursementOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse[1]1truetruetrue-0.0013-0.0013falsefalsefalse2truetruetrue-0.0014-0.0014falsefalsefalse3truetruetrue-0.0014-0.0014falsefalsefalse4truetruetrue00falsefalsefalserr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 false0Fee Waiver and/or Expense Reimbursement9falseRowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member11false 2rr_NetExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabelrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 true0Net Expensesfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 0rr_NetExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truetruetrue0.00930.0093falsefalsefalse2truetruetrue0.01680.0168falsefalsefalse3truetruetrue0.01680.0168falsefalsefalse4truetruetrue0.00820.0082falsefalsefalserr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 true0Net Expenses1After discussions with the Fund's Board of Trustees, the Manager has contractually agreed to waive fees and/or reimburse the Fund for certain expenses in order to limit "Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement" (excluding any applicable interest and fees from borrowing, interest and related expenses from inverse floaters, dividend expense, taxes, any subsidiary expenses, Acquired Fund Fees and Expenses, brokerage commissions, extraordinary expenses and certain other Fund expenses) to annual rates of 0.80% for Class A shares, 1.55% for Class B and Class C shares, and 0.80% for Class Y shares, as calculated on the daily net assets of the Fund. This fee waiver and/or expense reimbursement may not be amended or withdrawn for one year from the date of this prospectus, unless approved by the Board.falseAnnual Fund Operating Expenses (Oppenheimer Rochester North Carolina Municipal Fund)UnKnownUnKnownUnKnownUnKnownfalsefalsefalseSheet49273249085ColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Memberfalsenonnum:textBlockItemTypenaContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No definition available.false0Annual Fund Operating Expenses [Table]8false 2rr_ExpenseExampleNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Example. The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in a class of shares of the Fund for the time periods indicated. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your expenses would be as follows: falsefalsefalsenonnum:textBlockItemTypenaThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 1 false0Expense Example Narrative [Text Block]9false 2rr_ExpenseExampleByYearCaptionrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00If shares are redeemedfalsefalsefalsexbrli:stringItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2 false0Expense Example by, Year, Caption [Text]10false 2rr_ExpenseExampleWithRedemptionTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://ofirchncmuni-20130729/role/ExpenseExampleAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsefalse<div style="display:none">~ http://ofirchncmuni-20130729/role/ExpenseExampleAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>truehttp://ofirchncmuni-20130729/role/ExpenseExampleAAAA020032 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member3false 2rr_ExpenseExampleYear01rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 4 false21 Yearfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$2falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member4false 2rr_ExpenseExampleYear03rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2 false23 Yearsfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$3falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member5false 2rr_ExpenseExampleYear05rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2 false25 Yearsfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$4falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member6false 2rr_ExpenseExampleYear10rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. 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Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 2 -Subparagraph 1 false23 Yearsfalsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$3falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member5false 2rr_ExpenseExampleNoRedemptionYear05rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabelrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. 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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 6% of the average value of its portfolio. falsefalsefalsenonnum:textBlockItemTypenaDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 3 false0Portfolio Turnover [Text Block]14false 2rr_StrategyNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Principal Investment Strategies. Under normal market conditions, as a fundamental policy, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in securities the income from which, in the opinion of counsel to the issuer of each security, is exempt from both federal and North Carolina state income tax. These securities are generally issued by the state and its political subdivisions (such as cities, towns, counties, agencies and authorities) and primarily include municipal bonds (long-term (more than one-year) obligations), municipal notes (short-term obligations) and interests in municipal leases. Municipal securities generally are classified as general or revenue obligations. General obligations are secured by the issuer's pledge of its full faith, credit and taxing power for the payment of principal and interest. Revenue obligations are bonds whose interest is payable only from the revenues derived from a particular facility or class of facilities, or a specific excise tax or other revenue source. The securities in which the Fund invests may also include those of issuers located outside of North Carolina, such as U.S. territories, commonwealths and possessions, if the interest on such securities is not subject to federal or North Carolina state income tax. These securities are "North Carolina municipal securities" for purposes of this prospectus. Securities whose interest is exempt from North Carolina taxes are included for purposes of the Fund's 80% requirement discussed above, even if the issuer is located outside of North Carolina. Securities that generate income subject to alternative minimum tax (AMT) will count towards the Fund's 80% requirement. The Fund selects investments without regard to this type of tax treatment. Most of the securities the Fund buys are "investment-grade," although it can invest as much as 25% of its total assets in below investment-grade securities (commonly called "junk bonds"), which are subject to the special risks discussed below. Investment-grade securities are rated in one of the four highest rating categories of nationally recognized statistical rating organizations, such as Standard & Poor's (or, in the case of unrated securities, determined by the Fund's Sub-Adviser, OppenheimerFunds, Inc., to be comparable to securities rated investment-grade). The Fund also invests in unrated securities, in which case the Fund's Sub-Adviser, internally assigns ratings to those securities, after assessing their credit quality and other factors, in investment-grade or below-investment-grade categories similar to those of nationally recognized statistical rating organizations. There can be no assurance, nor is it intended, that the Sub-Adviser's credit analysis process is consistent or comparable with the credit analysis process used by a nationally recognized statistical rating organization. The Fund does not limit its investments to securities of a particular maturity range, and may hold both short- and long-term securities. However, the Fund currently focuses on longer-term securities to seek higher yields. This portfolio strategy is subject to change. The Fund may invest in obligations that pay interest at fixed or variable rates. The Fund can invest in inverse floating rate securities, a type of variable rate instrument, to seek increased income and return. Inverse floating rate securities are leveraged instruments and the extent of their leverage will vary depending on the security's characteristics. The Fund limits its investments in inverse floating rate securities as further described in this Prospectus under "Principal Risks." The Fund can borrow money to purchase additional securities, another form of leverage. Although the amount of borrowing will vary from time to time, the amount of leveraging from borrowings will not exceed one-third of the Fund's total assets. In selecting investments for the Fund, the portfolio managers look at a wide range of North Carolina municipal securities from different issuers that provide high current income, including unrated bonds, that have favorable credit characteristics and that provide opportunities for value. The portfolio managers may consider selling a security if any of these factors no longer applies to a security purchased for the Fund, but are not required to do so. falsefalsefalsenonnum:textBlockItemTypenaPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy Narrative [Text Block]15false 2rr_RiskNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Principal Risks. The price of the Fund's shares can go up and down substantially. The value of the Fund's investments may change because of broad changes in the markets in which the Fund invests or because of poor investment selection, which could cause the Fund to underperform other funds with similar investment objectives. There is no assurance that the Fund will achieve its investment objective. When you redeem your shares, they may be worth more or less than what you paid for them. These risks mean that you can lose money by investing in the Fund. Main Risks of Investing in Municipal Securities. Municipal securities may be subject to interest rate risk, duration risk, credit risk, credit spread risk, extension risk, reinvestment risk and prepayment risk. Interest rate risk is the risk that when prevailing interest rates fall, the values of already-issued debt securities generally rise; and when prevailing interest rates rise, the values of already-issued debt securities generally fall, and they may be worth less than the amount the Fund paid for them. When interest rates change, the values of longer-term debt securities usually change more than the values of shorter-term debt securities. Risks associated with rising interest rates are heightened given that interest rates in the U.S. are at, or near, historic lows. Duration risk is the risk that longer-duration debt securities will be more volatile and more likely to decline in price in a rising interest rate environment than shorter-duration debt securities. Credit risk is the risk that the issuer of a security might not make interest and principal payments on the security as they become due. If an issuer fails to pay interest or repay principal, the Fund's income or share value might be reduced. Adverse news about an issuer or a downgrade in an issuer's credit rating, for any reason, can also reduce the market value of the issuer's securities. "Credit spread" is the difference in yield between securities that is due to differences in their credit quality. There is a risk that credit spreads may increase when the market expects lower-grade bonds to default more frequently. Widening credit spreads may quickly reduce the market values of the Fund's lower-rated and unrated securities. Some unrated securities may not have an active trading market or may trade less actively than rated securities, which means that the Fund might have difficulty selling them promptly at an acceptable price. Extension risk is the risk that an increase in interest rates could cause principal payments on a debt security to be repaid at a slower rate than expected. Extension risk is particularly prevalent for a callable security where an increase in interest rates could result in the issuer of that security choosing not to redeem the security as anticipated on the security's call date. Such a decision by the issuer could have the effect of lengthening the debt security's expected maturity, making it more vulnerable to interest rate risk and reducing its market value. Reinvestment risk is the risk that when interest rates fall the Fund may be required to reinvest the proceeds from a security's sale or redemption at a lower interest rate. Callable bonds are generally subject to greater reinvestment risk than non-callable bonds. Prepayment risk is the risk that the issuer may redeem the security prior to the expected maturity or that borrowers may repay the loans that underlie these securities more quickly than expected, thereby causing the issuer of the security to repay the principal prior to the expected maturity. The Fund may need to reinvest the proceeds at a lower interest rate, reducing its income. Special Risks of Below-Investment-Grade Securities. Below-investment-grade debt securities (also referred to as "junk" bonds) may be subject to greater price fluctuations than investment-grade securities, increased credit risk and face a greater risk that the issuer might not be able to pay interest and principal when due, especially during times of weakening economic conditions or rising interest rates. The market for below-investment-grade securities may be less liquid and therefore these securities may be harder to value or sell, especially during times of market volatility or decline. Because the Fund can invest up to 25% of its assets in below-investment-grade securities, the Fund's credit risks are greater than those of funds that buy only investment-grade securities. This restriction is applied at the time of purchase and the Fund may continue to hold a security whose credit rating has been downgraded or, in the case of an unrated security, after the Fund's Sub-Adviser has changed its assessment of the security's credit quality. As a result, credit rating downgrades or other market fluctuations may cause the Fund's holdings of below-investment-grade securities to exceed, at times significantly, this restriction for an extended period of time. Credit rating downgrades of a single issuer or related similar issuers whose securities the Fund holds in significant amounts could substantially and unexpectedly increase the Fund's exposure to below-investment-grade securities and the risks associated with them, especially liquidity and default risk. If the Fund has more than 25% of its total assets invested in below-investment-grade securities, the Sub-Adviser will not purchase additional below-investment-grade securities until the level of holdings in those securities no longer exceeds the restriction. Special Risks of North Carolina Municipal Securities. Because the Fund invests primarily in North Carolina municipal securities, the value of its portfolio investments will be highly sensitive to events affecting the financial stability of the State of North Carolina and its municipalities, agencies, authorities and other instrumentalities that issue those securities. Budgetary stress on the state or its municipalities, changes in legislation or policy, erosion of the tax base, the effects of natural disasters, or other economic, legislative or political, or social issues may have a significant negative impact on the value of state or local securities. Special Risks of Investing in U.S. Territories, Commonwealths and Possessions. The Fund also invests in obligations of the governments of the U.S. territories, commonwealths and possessions such as Puerto Rico, the U.S. Virgin Islands, Guam, or the Northern Mariana Islands to the extent such obligations are exempt from state income taxes. These investments also are considered to be "North Carolina municipal securities" for purposes of this prospectus. Accordingly, the Fund may be adversely affected by local political, economic and social conditions and developments within these U.S. territories, commonwealths and possessions affecting the issuers of such obligations. Certain of the municipalities in which the Fund invests currently experience significant financial difficulties. A credit rating downgrade relating to, default by, or insolvency or bankruptcy of, one or several municipal security issuers of a state, territory, commonwealth or possession in which the Fund invests could affect the market values and marketability of many or all municipal obligations of such state, territory, commonwealth or possession. Municipal Market Volatility and Illiquidity. The municipal bond market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. During times of reduced market liquidity, the Fund may not be able to readily sell bonds at the prices at which they are carried on the Fund's books. If the Fund needed to sell large blocks of bonds to meet shareholder redemption requests or to raise cash, those sales could further reduce the bonds' prices. Municipal Sector Concentration. While the Fund does not invest more than 25% of its total assets in a single industry, certain types of municipal securities (such as general obligation, government appropriation, municipal leases, special assessment and special tax bonds) are not considered a part of any "industry" for purposes of this policy. Therefore, the Fund may invest more than 25% of its total assets in these types of municipal securities. These types of municipal securities may finance, or pay interest from the revenues of, projects that tend to be impacted in the same way by economic, business or political developments which would increase credit risk. For example, legislation on the financing of a project or a declining economic need for the project would likely affect all similar projects. Risks of Non-Diversification. The Fund is classified as a "non-diversified" fund under the Investment Company Act of 1940. Accordingly, the Fund may invest a greater portion of its assets in the securities of a single issuer than if it were a "diversified" fund. To the extent that the Fund invests a higher percentage of its assets in the securities of a single issuer, the Fund is more subject to the risks associated with and developments affecting that issuer than a fund that invests more widely. Risks of Tobacco Related Bonds. In 1998, the largest U.S. tobacco manufacturers reached an out of court agreement, known as the Master Settlement Agreement (the "MSA"), to settle claims against them by 46 states and six other U.S. jurisdictions. The tobacco manufacturers agreed to make annual payments to the government entities in exchange for the release of all litigation claims. A number of the states have sold bonds that are backed by those future payments. The Fund may invest in two types of those bonds: (i) bonds that make payments only from a state's interest in the MSA and (ii) bonds that make payments from both the MSA revenue and from an "appropriation pledge" by the state. An "appropriation pledge" requires the state to pass a specific periodic appropriation to make the payments and is generally not an unconditional guarantee of payment by a state. The settlement payments are based on factors, including, but not limited to, annual domestic cigarette shipments, cigarette consumption, inflation and the financial capability of participating tobacco companies. Payments could be reduced if consumption decreases, if market share is lost to non-MSA manufacturers, or if there is a negative outcome in litigation regarding the MSA, including challenges by participating tobacco manufacturers regarding the amount of annual payments owed under the MSA. The Fund can invest up to 25% of its total assets in tobacco-related bonds without an appropriation pledge that make payments only from a state's interest in the MSA. Risks of Land-Secured or "Dirt" Bonds. These special assessment or special tax bonds are issued to promote residential, commercial or industrial growth and redevelopment. They are exposed to real estate development-related risks. The bonds could default if the developments failed to progress as anticipated or if taxpayers failed to pay the assessments, fees and taxes specified in the financing plans for a project. Taxability Risk. The Fund's investments in municipal securities rely on the opinion of the issuer's bond counsel that the interest paid on those securities will not be subject to federal and state income tax. Income from tax-exempt municipal securities could be declared taxable because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service, state tax authorities, or a court, or the non-compliant conduct of a bond issuer. Main Risks of Borrowing and Leverage. The Fund can borrow up to one-third of the value of its total assets (including the amount borrowed) from banks, as permitted by the Investment Company Act of 1940. It can use those borrowings for a number of purposes, including for purchasing securities, which can create "leverage." In that case, changes in the value of the Fund's investments will have a larger effect on its share price than if it did not borrow. Borrowing results in interest payments to the lenders and related expenses. Borrowing for investment purposes might reduce the Fund's return if the yield on the securities purchased is less than those borrowing costs. The Fund may also borrow to meet redemption obligations, for temporary and emergency purposes, or to unwind or contribute to trusts in connection with the Fund's investment in inverse floaters (instruments also involving the use of leverage, as discussed below). The Fund currently participates in a line of credit with other Oppenheimer funds for its borrowing. The Fund can participate in a committed reverse repurchase agreement program. Reverse repurchase agreements that the Fund may engage in also create leverage. A reverse repurchase agreement is the sale by the Fund of a debt obligation to a party for a specified price, with the simultaneous agreement by the Fund to repurchase that debt obligation from that party on a future date at a higher price. Similar to a borrowing, reverse repurchase agreements provide the Fund with cash for investment and operational purposes. When the Fund engages in reverse repurchase agreements, changes in the value of the Fund's investments will have a larger effect on its share price than if it did not engage in these transactions due to the effect of leverage. Reverse repurchase agreements create fund expenses and require that the Fund have sufficient cash available to repurchase the debt obligation when required. Reverse repurchase agreements also involve the risk that the market value of the debt obligation that is the subject of the reverse repurchase agreement could decline significantly below the price at which the Fund is obligated to repurchase the security. Main Risks of Derivative Investments. Derivatives may involve significant risks. Derivatives may be more volatile than other types of investments, require the payment of premiums, can increase portfolio turnover, may be illiquid, and may not perform as expected. Derivatives are subject to counterparty risk and the Fund may lose money on a derivative investment if the issuer or counterparty fails to pay the amount due. Some derivatives have the potential for unlimited loss, regardless of the size of the Fund's initial investment. As a result of these risks, the Fund could realize little or no income or lose money from its investment, or a hedge might be unsuccessful. In addition, under new rules enacted and currently being implemented under U.S. financial reform legislation, certain over-the-counter derivatives are (or soon will be) required to be executed on a regulated market and cleared through a central clearing house counterparty. It is unclear how these regulatory changes will affect counterparty risk, and entering into a derivative transaction with a central clearing house counterparty may entail further risks and costs. Inverse Floaters. The Fund invests in inverse floating rate securities ("inverse floaters") because, under ordinary circumstances, they offer higher yields and thus provide higher income than fixed-rate municipal bonds of comparable maturity and credit quality. Because inverse floaters are leveraged instruments, the value of an inverse floater will change more significantly in response to changes in interest rates and other market fluctuations than the market value of a conventional fixed-rate municipal security of comparable maturity and credit quality, including the municipal bond underlying an inverse floater. During periods of rising interest rates, the market values of inverse floaters will tend to decline more quickly than those of fixed-rate securities. An inverse floater is created when a fixed-rate municipal bond is contributed to a trust. The trust issues two separate classes of securities: short-term floating rate securities with a fixed principal amount that represent a senior interest in the underlying municipal bond, and the inverse floater that represents a residual, subordinate interest in the underlying municipal bond. The trust issues and sells the short-term floating rate securities to third parties and the inverse floater to the Fund. The short-term floating rate securities generally bear short-term rates of interest. When interest is paid on the underlying municipal bond to the trust, such proceeds are first used to pay interest owing to holders of the short-term floating rate securities, with any remaining amounts being paid to the Fund, as the holder of the inverse floater. Accordingly, the amount of such interest paid to the Fund is inversely related to the rate of interest on the short-term floating rate securities. Inverse floaters produce less income when short-term interest rates rise (and, in extreme cases, may pay no income) and more income when short-term interest rates fall. Thus, if short-term interest rates rise after the issuance of the inverse floater, any yield advantage to the Fund is reduced and may be eliminated. Additionally, because the principal amount of the short-term floating rate security is fixed and is not adjusted in response to changes in the market value of the underlying municipal bond, any change in the market value of the underlying municipal bond is reflected entirely in a change to the value of the inverse floater. Upon the occurrence of certain adverse events, a trust may be collapsed and the underlying municipal bond liquidated, and the Fund could lose the entire amount of its investment in the inverse floater and may, in some cases, be contractually required to pay the negative difference, if any, between the liquidation value of the underlying municipal bond and the principal amount of the short-term floating rate securities. The Fund may invest in inverse floaters with any degree of leverage (measured by comparing the outstanding principal amount of related short-term floating rate securities to the par value of the underlying municipal bond). However, the Fund may only expose up to 20% of its total assets to the effects of leverage from its investments in inverse floaters. This limitation is measured by comparing the aggregate principal amount of the short-term floating rate securities that are related to the inverse floaters held by the Fund to the total assets of the Fund. Nevertheless, the value of, and income earned on, an inverse floater that has a higher degree of leverage (represented by a larger outstanding principal amount of related short-term floating rate securities) will fluctuate more significantly in response to changes in interest rates and to changes in the market value of the related underlying municipal bond, and are more likely to be eliminated entirely under adverse market conditions. Who Is The Fund Designed For? The Fund is designed for investors seeking income exempt from federal and North Carolina state personal income taxes. The Fund does not seek capital gains or growth. Because it invests in tax-exempt securities, the Fund is not appropriate for retirement plan accounts or for investors seeking capital growth. The Fund is not a complete investment program. You should carefully consider your own investment goals and risk tolerance before investing. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. falsefalsefalsenonnum:textBlockItemTypenaNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 1 -Subparagraph i -Clause instruction false0Risk Narrative [Text Block]16false 2rr_PerformanceNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 The Fund's Past Performance. The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance (for Class A shares) from year to year and by showing how the Fund's average annual returns for 1 year, 5 years and the life of the Fund compare with those of a broad measure of market performance. The Fund's past investment performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More recent performance information is available by calling the toll-free number on the back of this prospectus and on the Fund's website: https://www.oppenheimerfunds.com/fund/RochesterNorthCarolinaMunicipalFund falsefalsefalsenonnum:textBlockItemTypenaRisk/Return Bar Chart and Table.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 false0Performance Narrative [Text Block]17false 2rr_BarChartTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://ofirchncmuni-20130729/role/BarChartDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>falsefalseBarChart1.jpg<div style="display:none">~ http://ofirchncmuni-20130729/role/BarChartDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact ofirchncmuni-20130729_S000012508Member ~</div>truehttp://ofirchncmuni-20130729/role/BarChartDataAAAA020052 - Schedule - Annual Total Returns {Transposed}truefalsefalse1falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member3false3false 2rr_AnnualReturn2007rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0346-0.0346falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2007 2rr_AnnualReturn2007rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2007falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$2falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member4false4false 2rr_AnnualReturn2008rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3649-0.3649falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2008 2rr_AnnualReturn2008rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2008falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$3falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member5false5false 2rr_AnnualReturn2009rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.45380.4538falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2009 2rr_AnnualReturn2009rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2009falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$4falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member6false6false 2rr_AnnualReturn2010rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.03880.0388falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2010 2rr_AnnualReturn2010rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2010falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$5falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member7false7false 2rr_AnnualReturn2011rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12620.1262falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2011 2rr_AnnualReturn2011rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a false0Annual Return 2011falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$6falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member8false8false 2rr_AnnualReturn2012rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12170.1217falsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2012 2rr_AnnualReturn2012rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Annual Return 2012falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$1falseRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*Rowdei_DocumentInformationDocumentAxisAxis*RowunitUnit*duration2013-07-29T00:00:002013-07-29T00:00:00falsefalseClass Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_C000034012Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalsedei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberClass ARatioStandardhttp://www.xbrl.org/2003/instancepurexbrli0Standard0 0truefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0346-0.0346falsefalsefalse2truetruefalse-0.3649-0.3649falsefalsefalse3truetruefalse0.45380.4538falsefalsefalse4truetruefalse0.03880.0388falsefalsefalse5truetruefalse0.12620.1262falsefalsefalse6truetruefalse0.12170.1217falsefalsefalsenanafalse0Class AfalseAnnual Total Returns (Oppenheimer Rochester North Carolina Municipal Fund)UnKnownUnKnownUnKnownUnKnownfalsefalsefalseSheet615061036ColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508MemberRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*Rowdei_DocumentInformationDocumentAxisAxis*RowunitUnit*falsenonnum:textBlockItemTypenaContains a command for the SEC Viewer for the role corresponding to BarChartData.No definition available.false0Bar Chart [Table]18false 2rr_BarChartClosingTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Sales charges and taxes are not included and the returns would be lower if they were. During the period shown, the highest return for a calendar quarter was 19.74% (3rd Qtr 09) and the lowest return was -24.01% (4th Qtr 08). For the period from January 1, 2013 to June 30, 2013 the cumulative return before sales charges and taxes was -3.26%. falsefalsefalsenonnum:textBlockItemTypenaIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph ii false0Bar Chart Closing [Text Block]19false 2rr_PerformanceTableHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Average Annual Total Returns for the periods ended December 31, 2012 falsefalsefalsexbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit c false0Performance Table Heading20false 2rr_PerformanceTableNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 The following table shows the average annual total returns for each class of the Fund's shares. After-tax returns are calculated using the highest individual federal marginal income tax rates and do not reflect the impact of state or local taxes. Your actual after-tax returns, depending on your individual tax situation, may differ from those shown and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for only one class and after-tax returns for other classes will vary. falsefalsefalsenonnum:textBlockItemTypenaIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph iv false0Performance Table Narrative21false 2rr_PerformanceTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://ofirchncmuni-20130729/role/PerformanceTableDataAAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact 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Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) USDfalsefalse$2falseColumnprimaryElement*Columndei_LegalEntityAxisAxisofirchncmuni-20130729_S000012508Member4false 2rr_AverageAnnualReturnYear05rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsexbrli:pureItemTypepureReturn Before Taxes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 false05 Years (or life of class, if less)falsefalse(Oppenheimer Rochester North Carolina Municipal Fund)dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiofirchncmuni-20130729_S000012508Memberdei_LegalEntityAxisexplicitMember(Oppenheimer Rochester North Carolina Municipal Fund) 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