1.0.0.3 false CONSOLIDATED BALANCE SHEETS (USD $) In Thousands 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 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 4 Current assets 2 us-gaap_AssetsCurrentAbstract 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 No definition available. false 5 Cash and cash equivalents 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 3151000 3151 false false 2 true true 177635000 177635 false false No definition available. No authoritative reference available. false 6 Accounts receivable, net 3 us-gaap_ReceivablesNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 624635000 624635 false false 2 false true 317182000 317182 false false No definition available. No authoritative reference available. false 7 Affiliate receivables 3 us-gaap_DueFromRelatedPartiesCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 32397000 32397 false false 2 false true 25776000 25776 false false No definition available. No authoritative reference available. false 8 Gas and natural gas liquids in storage 3 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 217585000 217585 false false 2 false true 190616000 190616 false false No definition available. No authoritative reference available. false 9 Commodity imbalances 3 oks_CommodityExchangesAndImbalances oks false debit instant monetary Carrying amount as of the balance sheet date of the asset arising from natural gas pipeline imbalances or natural gas liquid... false false false false false false false false false 1 false true 188177000 188177 false false 2 false true 55086000 55086 false false Carrying amount as of the balance sheet date of the asset arising from natural gas pipeline imbalances or natural gas liquid exchange agreements valued at market or their contractually stipulated rate. Natural gas imbalances and natural gas liquid exchange agreements are settled in cash or made up in kind within one year, according to the terms of the respective pipeline tariff or by exchange agreement. No authoritative reference available. false 10 Derivative financial instruments (Notes C and D) 3 us-gaap_DerivativeInstrumentsAndHedges us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 63780000 63780 false false No definition available. No authoritative reference available. false 11 Other current assets 3 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 36148000 36148 false false 2 false true 28176000 28176 false false No definition available. No authoritative reference available. false 12 Total current assets 3 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1102093000 1102093 false false 2 false true 858251000 858251 false false No definition available. No authoritative reference available. true 13 Property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNetAbstract 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 No definition available. false 14 Property, plant and equipment 3 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 6353909000 6353909 false false 2 false true 5808679000 5808679 false false No definition available. No authoritative reference available. false 15 Accumulated depreciation and amortization 3 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 972497000 972497 false false 2 false true 875279000 875279 false false No definition available. No authoritative reference available. false 16 Net property, plant and equipment (Note E) 3 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5381412000 5381412 false false 2 false true 4933400000 4933400 false false No definition available. No authoritative reference available. true 17 Investments and other assets 2 oks_InvestmentsAndOtherAssets oks false 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 No definition available. false 18 Investments in unconsolidated affiliates (Note N) 3 us-gaap_EquityMethodInvestments us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 765163000 765163 false false 2 false true 755492000 755492 false false No definition available. No authoritative reference available. false 19 Goodwill and intangible assets (Note F) 3 oks_GoodwillAndIntangibleAssets oks false debit instant monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized... false false false false false false false false false 1 false true 668870000 668870 false false 2 false true 676536000 676536 false false Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions and the sum of the carrying amounts of all intangible assets as of the balance date, net of accumulated amortization and impairment charges. No authoritative reference available. false 20 Other assets 3 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 35721000 35721 false false 2 false true 30593000 30593 false false No definition available. No authoritative reference available. false 21 Total investments and other assets 3 oks_TotalInvestmentsAndOtherAssets oks false debit instant monetary Sum of the carrying amounts as of the balance sheet date of all assets, excluding property, plant and equipment, that are... false false false false false false false false false 1 false true 1469754000 1469754 false false 2 false true 1462621000 1462621 false false Sum of the carrying amounts as of the balance sheet date of all assets, excluding property, plant and equipment, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. No authoritative reference available. true 22 Total assets 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 7953259000 7953259 false false 2 false true 7254272000 7254272 false false No definition available. No authoritative reference available. true 24 Current liabilities 2 us-gaap_LiabilitiesCurrentAbstract 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 No definition available. false 25 Current maturities of long-term debt (Note I) 3 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 261931000 261931 false false 2 false true 11931000 11931 false false No definition available. No authoritative reference available. false 26 Notes payable (Note H) 3 us-gaap_ShortTermBankLoansAndNotesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 523000000 523000 false false 2 false true 870000000 870000 false false No definition available. No authoritative reference available. false 27 Accounts payable 3 us-gaap_AccountsPayableCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 694290000 694290 false false 2 false true 496763000 496763 false false No definition available. No authoritative reference available. false 28 Affiliate payables 3 us-gaap_DueToRelatedPartiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 21866000 21866 false false 2 false true 23333000 23333 false false No definition available. No authoritative reference available. false 29 Commodity imbalances 3 oks_CommodityExchangesAndImbalancesLiabilities oks false credit instant monetary Carrying amount as of the balance sheet date of the liability arising from natural gas pipeline imbalances or natural gas... false false false false false false false false false 1 false true 392688000 392688 false false 2 false true 191165000 191165 false false Carrying amount as of the balance sheet date of the liability arising from natural gas pipeline imbalances or natural gas liquid exchange agreements valued at market or their contractually stipulated rate. Natural gas imbalances and natural gas liquid exchange agreements are settled in cash or made up in kind within one year, according to the terms of the respective pipeline tariff or by exchange agreement. No authoritative reference available. false 30 Other current liabilities 3 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 153539000 153539 false false 2 false true 100832000 100832 false false No definition available. No authoritative reference available. false 31 Total current liabilities 3 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2047314000 2047314 false false 2 false true 1694024000 1694024 false false No definition available. No authoritative reference available. true 32 Long-term debt, excluding current maturities (Note I) 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2822086000 2822086 false false 2 false true 2589509000 2589509 false false No definition available. No authoritative reference available. false 33 Deferred credits and other liabilities 2 oks_TotalDeferredCreditsAndOtherLiabilities oks false credit instant monetary Total obligations, excluding long-term debt, incurred as part of normal operations that is expected to be repaid beyond the... false false false false false false false false false 1 false true 73798000 73798 false false 2 false true 54773000 54773 false false Total obligations, excluding long-term debt, incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. No authoritative reference available. false 36 ONEOK Partners, L.P. partners' equity: 3 us-gaap_PartnersCapitalAbstract 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 No definition available. false 37 General partner 4 us-gaap_GeneralPartnersCapitalAccount us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 84434000 84434 false false 2 false true 77546000 77546 false false No definition available. No authoritative reference available. false 38 Common units: 59,912,777 and 54,426,087 units issued and outstanding at December 31, 2009 and 2008, respectively 4 us-gaap_LimitedPartnersCapitalAccount us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1561762000 1561762 false false 2 false true 1361058000 1361058 false false No definition available. No authoritative reference available. false 39 Class B units: 36,494,126 units issued and outstanding at December 31, 2009 and 2008 4 oks_ClassBUnitsPartnersCapitalAccount oks false credit instant monetary The Class B limited partner's ownership share in the capital account balance. The Class B limited partners are partners of a... false false false false false false false false false 1 false true 1380299000 1380299 false false 2 false true 1407016000 1407016 false false The Class B limited partner's ownership share in the capital account balance. The Class B limited partners are partners of a publicly traded limited partnership or master limited partnership. Limited partners have limited liability and do not manage the partnership. No authoritative reference available. false 40 Accumulated other comprehensive income (loss) (Note G) 4 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -22037000 -22037 false false 2 false true 64405000 64405 false false No definition available. No authoritative reference available. false 41 Total ONEOK Partners, L.P. partners' equity 4 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 3004458000 3004458 false false 2 false true 2910025000 2910025 false false No definition available. No authoritative reference available. true 42 Noncontrolling interests in consolidated subsidiaries 3 us-gaap_MinorityInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5603000 5603 false false 2 false true 5941000 5941 false false No definition available. No authoritative reference available. false 43 Total partners' equity 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 3010061000 3010061 false false 2 false true 2915966000 2915966 false false No definition available. No authoritative reference available. true 44 Total liabilities and partners' equity 3 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 7953259000 7953259 false false 2 true true 7254272000 7254272 false false No definition available. No authoritative reference available. true false 2 38 false Thousands UnKnown UnKnown false true