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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 false 4 Segment costs and expenses: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 5 Costs and operating expenses 2 wpz_CostsAndOperatingExpenses wpz false debit duration Costs And Operating Expenses. false false false false false false false false false false false verboselabel false 1 false true false false 908000000 908 false false false 2 false true false false 793000000 793 [1] false false false 3 false true false false 2909000000 2909 false false false 4 false true false false 2174000000 2174 [1] false false false xbrli:monetaryItemType monetary Costs And Operating Expenses. No authoritative reference available. false 6 Selling, general and administrative expenses 2 us-gaap_SellingGeneralAndAdministrativeExpense us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 67000000 67 false false false 2 false true false false 72000000 72 [1] false false false 3 false true false false 194000000 194 false false false 4 false true false false 213000000 213 [1] false false false xbrli:monetaryItemType monetary The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. 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No authoritative reference available. true 10 Operating income: 2 us-gaap_OperatingIncomeLossAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 12 Total operating income 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 290000000 290 false false false 2 false true false false 291000000 291 [1] false false false 3 false true false false 935000000 935 false false false 4 false true false false 756000000 756 [1] false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. false 13 Equity earnings 2 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 24000000 24 false false false 2 false true false false 30000000 30 [1] false false false 3 false true false false 77000000 77 false false false 4 false true false false 51000000 51 [1] false false false xbrli:monetaryItemType monetary This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Such amount typically reflects adjustments similar to those made in preparing consolidated statements, including adjustments to eliminate intercompany gains and losses, and to amortize, if appropriate, any difference between cost and underlying equity in net assets of the investee at the date of investment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 19 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 11 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 9 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 6 -Subparagraph b false 14 Interest accrued - third-party 2 wpz_InterestAccruedThirdParty wpz false credit duration Interest accrued - third-party. false false false false false false false false false false false verboselabel false 1 false true false false -103000000 -103 false false false 2 false true false false -51000000 -51 [1] false false false 3 false true false false -285000000 -285 false false false 4 false true false false -153000000 -153 [1] false false false xbrli:monetaryItemType monetary Interest accrued - third-party. No authoritative reference available. false 15 Interest accrued - affiliate 2 wpz_InterestAccruedAffiliate wpz false credit duration Interest accrued affiliate. false false false false false false false false false false false verboselabel false 1 false false false false 0 0   false false false 2 false true false false -9000000 -9 [1] false false false 3 false true false false -1000000 -1 false false false 4 false true false false -39000000 -39 [1] false false false xbrli:monetaryItemType monetary Interest accrued affiliate. 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No authoritative reference available. false 18 Other income - net 2 us-gaap_OtherNonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 9000000 9 false false false 2 false true false false 4000000 4 [1] false false false 3 false true false false 10000000 10 false false false 4 false true false false 9000000 9 [1] false false false xbrli:monetaryItemType monetary The net amount of other nonoperating income and expense, which does not qualify for separate disclosure on the income statement under materiality guidelines. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 9 -Article 5 true 19 Income before income taxes 2 wpz_IncomeBeforeIncomeTaxes wpz false credit duration Income before income taxes. false false false false false false false false false false false verboselabel false 1 false true false false 227000000 227 false false false 2 false true false false 280000000 280 [1] false false false 3 false true false false 765000000 765 false false false 4 false true false false 681000000 681 [1] false false false xbrli:monetaryItemType monetary Income before income taxes. No authoritative reference available. false 20 Provision for income taxes 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1000000 1 false false false 2 false true false false 1000000 1 [1] false false false 3 false true false false 1000000 1 false false false 4 false true false false 4000000 4 [1] false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 21 Net income 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 226000000 226 false false false 2 false true false false 279000000 279 [1] false false false 3 false true false false 764000000 764 false false false 4 false true false false 677000000 677 [1] false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. 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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 true 23 Net income attributable to controlling interests 2 us-gaap_NetIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 221000000 221 false false false 2 false true false false 272000000 272 [1] false false false 3 false true false false 748000000 748 false false false 4 false true false false 657000000 657 [1] false false false xbrli:monetaryItemType monetary The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes. 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No authoritative reference available. true 27 Allocation of net income to common units 2 us-gaap_NetIncomeLossAllocatedToLimitedPartners us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 163000000 163 false false false 2 false true false false 55000000 55 [1] false false false 3 false true false false 355000000 355 false false false 4 false true false false 100000000 100 [1] false false false xbrli:monetaryItemType monetary Aggregate amount of net income allocated to general partners in a publicly trade limited partnership or master limited partnership (MLP). Limited partners have limited liability and do not manage the partnership. No authoritative reference available. true 28 Basic and diluted net income per common unit 2 wpz_BasicAndDilutedNetIncomePerCommonUnits wpz false na duration Basic and diluted net income per common units. false false false false false false false false false false false verboselabel true 1 true true false false 0.63 0.63 false false false 2 true true false false 1.04 1.04 [1] false false false 3 true true false false 1.87 1.87 false false false 4 true true false false 1.88 1.88 [1] false false false us-types:perShareItemType decimal Basic and diluted net income per common units. 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