2.0.0.10 true CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' EQUITY (USD $) 004000 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' EQUITY true false In Thousands, except Share data false false 1 usd $ true false false false oks_GeneralPartnersMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi oks_GeneralPartnersMember us-gaap_StatementEquityComponentsAxis explicitMember u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 usd $ true false false false oks_CommonUnitsMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi oks_CommonUnitsMember us-gaap_StatementEquityComponentsAxis explicitMember u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 false 3 usd $ true false false false oks_ClassBUnitsMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi oks_ClassBUnitsMember us-gaap_StatementEquityComponentsAxis explicitMember u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 false 4 usd $ true false false false us-gaap_AccumulatedOtherComprehensiveIncomeMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AccumulatedOtherComprehensiveIncomeMember us-gaap_StatementEquityComponentsAxis explicitMember u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 5 usd $ true false false false us-gaap_NoncontrollingInterestMember us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NoncontrollingInterestMember us-gaap_StatementEquityComponentsAxis explicitMember u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 6 usd $ false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 6 Partners' capital account, units, beginning balance at Dec. 31, 2009 3 us-gaap_PartnersCapitalAccountUnits us-gaap true na instant shares No definition available. false false false true false false false false true false false periodstartlabel false 1 false false false false 0 0 true false false 2 false true false false 59912777 59912777.00 true false false 3 false true false false 36494126 36494126.00 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false The number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners of a publicly listed limited partnership or a master limited partnership. General partners have unlimited liability and manage the partnership. Limited partners have limited liability and do not manage the partnership. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 16 -Subparagraph a, b -Article 6 false 5 Partners' capital, beginning balance at Dec. 31, 2009 3 us-gaap_PartnersCapital us-gaap true credit instant monetary No definition available. false false false true false false false false true false false periodstartlabel false 1 true true false false 84434000 84434 true false false 2 true true false false 1561762000 1561762 true false false 3 true true false false 1380299000 1380299 true false false 4 true true false false -22037000 -22037 true false false 5 true true false false 5603000 5603 true false false 6 true true false false 3010061000 3010061 false false false Ownership interest of different classes of partners in the publicly listed limited partnership or master limited partnership. Partners include general, limited and preferred partners. Limited liability partnerships (LLPs) are formed in accordance with the laws of the state in which such entities are organized. Because those laws are not uniform, the characteristics of LPCs vary from state to state. However, LLPs generally have the following characteristics: An LLP is an unincorporated association of two or more "persons"; Its members have limited personal liability for the obligations or debts of the entity; It is classified as a partnership for federal income tax purposes. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 false 7 Net income 3 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false false false false 1 false true false false 27387000 27387 true false false 2 false true false false 35432000 35432 true false false 3 false true false false 21049000 21049 true false false 4 false true false false 0 0 true false false 5 false true false false 152000 152 true false false 6 false true false false 84020000 84020 false false false The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 8 Other comprehensive income (Note D) 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false false false label false 1 false true false false 0 0 true false false 2 false true false false 0 0 true false false 3 false true false false 0 0 true false false 4 false true false false 29355000 29355 true false false 5 false true false false 0 0 true false false 6 false true false false 29355000 29355 false false false This element represents Other Comprehensive Income (Loss), Net of Tax, for the period. Includes deferred gains (losses) on qualifying hedges, unrealized holding gains (losses) on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 22, 23, 24, 25 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 false 9 Issuance of common units, value (Note F) 3 us-gaap_PartnersCapitalAccountSaleOfUnits us-gaap true credit duration monetary No definition available. false false false false false false false false false false false label false 1 false true false false 0 0 true false false 2 false true false false 322721000 322721 true false false 3 false true false false 0 0 true false false 4 false true false false 0 0 true false false 5 false true false false 0 0 true false false 6 false true false false 322721000 322721 false false false Total change in each class of partners' capital accounts during the year due to the sale of units. All partners include general, limited and preferred partners. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 false 10 Issuance of common units, units (Note F) 3 us-gaap_PartnersCapitalAccountUnitsSaleOfUnits us-gaap true na duration shares No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 true false false 2 false true false false 5500900 5500900.00 true false false 3 false true false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false Total units issued during the year due to the sale of units. All partners include general, limited and preferred partners. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 false 11 Contribution from general partner (Note F) 3 oks_PartnersCapitalAccountContributionFromGeneralPartner oks false credit duration monetary Total contribution made by general partner during the reporting period. false false false false false false false false false false false terselabel false 1 false true false false 6820000 6820 true false false 2 false true false false 0 0 true false false 3 false true false false 0 0 true false false 4 false true false false 0 0 true false false 5 false true false false 0 0 true false false 6 false true false false 6820000 6820 false false false Total contribution made by general partner during the reporting period. No authoritative reference available. false 12 Distributions paid (Note F) 3 us-gaap_PartnersCapitalAccountDistributions us-gaap true debit duration monetary No definition available. false false false false false false false false false false false label false 1 false true false false -26039000 -26039 true false false 2 false true false false -65904000 -65904 true false false 3 false true false false -40143000 -40143 true false false 4 false true false false 0 0 true false false 5 false true false false -368000 -368 true false false 6 false true false false -132454000 -132454 false false false Total distributions to each class of partners (i.e., general, limited and preferred partners). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 false 13 Partners' capital, ending balance at Mar. 31, 2010 3 us-gaap_PartnersCapital us-gaap true credit instant monetary No definition available. false false false true false false false false false true false periodendlabel false 1 true true false false 92602000 92602 true false false 2 true true false false 1854011000 1854011 true false false 3 true true false false 1361205000 1361205 true false false 4 true true false false 7318000 7318 true false false 5 true true false false 5387000 5387 true false false 6 true true false false 3320523000 3320523 false false false Ownership interest of different classes of partners in the publicly listed limited partnership or master limited partnership. Partners include general, limited and preferred partners. Limited liability partnerships (LLPs) are formed in accordance with the laws of the state in which such entities are organized. Because those laws are not uniform, the characteristics of LPCs vary from state to state. However, LLPs generally have the following characteristics: An LLP is an unincorporated association of two or more "persons"; Its members have limited personal liability for the obligations or debts of the entity; It is classified as a partnership for federal income tax purposes. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 false 14 Partners' capital account, units, ending balance at Mar. 31, 2010 3 us-gaap_PartnersCapitalAccountUnits us-gaap true na instant shares No definition available. false false false true false false false false false true false periodendlabel false 1 false false false false 0 0 true false false 2 false true false false 65413677 65413677.00 true false false 3 false true false false 36494126 36494126.00 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 false false false The number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners of a publicly listed limited partnership or a master limited partnership. General partners have unlimited liability and manage the partnership. Limited partners have limited liability and do not manage the partnership. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 16 -Subparagraph a, b -Article 6 false false 6 10 false Thousands NoRounding UnKnown false true