1.0.0.3 false CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data false 1 $ 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 false 2 $ 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 false 3 $ 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 2 Income Statement 0 us-gaap_IncomeStatementAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 3 Revenues 1 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 6474491000 6474491 false false 2 true true 7720206000 7720206 false false 3 true true 5831558000 5831558 false false No definition available. No authoritative reference available. false 4 Cost of sales and fuel 1 us-gaap_CostOfRevenue us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 5355194000 5355194 false false 2 false true 6579547000 6579547 false false 3 false true 4935665000 4935665 false false No definition available. No authoritative reference available. false 5 Net margin 1 us-gaap_GrossProfit us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1119297000 1119297 false false 2 false true 1140659000 1140659 false false 3 false true 895893000 895893 false false No definition available. No authoritative reference available. true 6 Operating expenses 1 us-gaap_OperatingExpensesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 7 Operations and maintenance 2 oks_OperationsAndMaintenance oks false debit duration monetary Expenses incurred for the administration, supervision, operation, maintenance, preservation, and protection of the entity's... false false false false false false false false false 1 false true 361608000 361608 false false 2 false true 337526000 337526 false false 3 false true 302544000 302544 false false Expenses incurred for the administration, supervision, operation, maintenance, preservation, and protection of the entity's business. No authoritative reference available. false 8 Depreciation and amortization 2 us-gaap_DepreciationDepletionAndAmortization us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 164136000 164136 false false 2 false true 124765000 124765 false false 3 false true 113704000 113704 false false No definition available. No authoritative reference available. false 9 General taxes 2 oks_GeneralTaxes oks false debit duration monetary General taxes including primarily payroll and ad valorem. false false false false false false false false false 1 false true 49619000 49619 false false 2 false true 34271000 34271 false false 3 false true 34812000 34812 false false General taxes including primarily payroll and ad valorem. No authoritative reference available. false 10 Total operating expenses 2 us-gaap_OperatingExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 575363000 575363 false false 2 false true 496562000 496562 false false 3 false true 451060000 451060 false false No definition available. No authoritative reference available. true 11 Gain on sale of assets 1 us-gaap_GainLossOnDispositionOfAssets us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 2668000 2668 false false 2 false true 713000 713 false false 3 false true 1950000 1950 false false No definition available. No authoritative reference available. false 12 Operating income 1 us-gaap_OperatingIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 546602000 546602 false false 2 false true 644810000 644810 false false 3 false true 446783000 446783 false false No definition available. No authoritative reference available. true 13 Equity earnings from investments (Note N) 1 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 72722000 72722 false false 2 false true 101432000 101432 false false 3 false true 89908000 89908 false false No definition available. No authoritative reference available. false 14 Allowance for equity funds used during construction 1 oks_AllowanceForEquityFundsUsedDuringConstruction oks false credit duration monetary The cost of equity related to financing the construction of regulated assets. false false false false false false false false false 1 false true 26868000 26868 false false 2 false true 50906000 50906 false false 3 false true 12538000 12538 false false The cost of equity related to financing the construction of regulated assets. No authoritative reference available. false 15 Other income 1 us-gaap_OtherNonoperatingIncome us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 10658000 10658 false false 2 false true 5621000 5621 false false 3 false true 7502000 7502 false false No definition available. No authoritative reference available. false 16 Other expense 1 us-gaap_OtherNonoperatingExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -3167000 -3167 false false 2 false true -13321000 -13321 false false 3 false true -779000 -779 false false No definition available. No authoritative reference available. false 17 Interest expense 1 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -206016000 -206016 false false 2 false true -151056000 -151056 false false 3 false true -138947000 -138947 false false No definition available. No authoritative reference available. false 18 Income before income taxes 1 oks_IncomeBeforeIncomeTaxes oks false credit duration monetary Sum of operating profit and nonoperating income (expense) before income taxes, extraordinary items, cumulative effects of... false false false false false false false false false 1 false true 447667000 447667 false false 2 false true 638392000 638392 false false 3 false true 417005000 417005 false false Sum of operating profit and nonoperating income (expense) before income taxes, extraordinary items, cumulative effects of changes in accounting principles and noncontrolling interest. No authoritative reference available. true 19 Income taxes (Note L) 1 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -12963000 -12963 false false 2 false true -12335000 -12335 false false 3 false true -8842000 -8842 false false No definition available. No authoritative reference available. false 20 Net income 1 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 434704000 434704 false false 2 false true 626057000 626057 false false 3 false true 408163000 408163 false false No definition available. No authoritative reference available. true 21 Less: Net income attributable to noncontrolling interests 1 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 348000 348 false false 2 false true 441000 441 false false 3 false true 416000 416 false false No definition available. No authoritative reference available. false 22 Net income attributable to ONEOK Partners, L.P. 1 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 434356000 434356 false false 2 false true 625616000 625616 false false 3 false true 407747000 407747 false false No definition available. No authoritative reference available. true 23 Limited partners' interest in net income: 1 us-gaap_PartnershipIncomeAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 24 Net income attributable to ONEOK Partners, L.P. 2 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 434356000 434356 false false 2 false true 625616000 625616 false false 3 false true 407747000 407747 false false No definition available. No authoritative reference available. false 25 General partner's interest in net income 2 us-gaap_NetIncomeLossAllocatedToGeneralPartners us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -96421000 -96421 false false 2 false true -88554000 -88554 false false 3 false true -58781000 -58781 false false No definition available. No authoritative reference available. false 26 Limited partners' interest in net income 2 us-gaap_NetIncomeLossAllocatedToLimitedPartners us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 337935000 337935 false false 2 true true 537062000 537062 false false 3 true true 348966000 348966 false false No definition available. No authoritative reference available. true 27 Limited partners' net income per unit, basic and diluted (Note O) 1 us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnit us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 3.60 3.60 false false 2 true true 6.01 6.01 false false 3 true true 4.21 4.21 false false No definition available. No authoritative reference available. false 28 Number of units used in computation (thousands) 1 us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 93808000 93808 false false 2 false true 89309000 89309 false false 3 false true 82891000 82891 false false No definition available. No authoritative reference available. false false 3 27 false Thousands Thousands Hundreds false true