Goodwill and Intangible Assets Disclosure [Abstract] Goodwill Goodwill Disclosure [Text Block] Leases [Abstract] Lessee, Lease, Assets and Liabilities [Table] Lessee, Lease, Description [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Property and equipment Property, Plant and Equipment [Member] Accumulated depreciation Accumulated Depreciation [Member] Accumulated Depreciation [Member] Property and equipment, net Property and Equipment, Net [Member] Property and Equipment, Net [Member] Other current liabilities Other Current Liabilities [Member] Short-term debt Short-term Debt [Member] Other long-term debt, net Other Long Term Debt [Member] Other types of long-term debt not specifically identified. Lessee, Lease, Assets and Liabilities [Line Items] Lessee, Lease, Description [Line Items] Long-term operating lease right-of-use assets, net Operating Lease, Right-of-Use Asset Finance lease right-of-use assets, gross Finance Lease, Right-Of-Use Asset, Gross Finance Lease, Right-Of-Use Asset, Gross Finance lease right-of-use assets, accumulated depreciation Finance Lease, Right-Of-Use Asset, Accumulated Depreciation Finance Lease, Right-Of-Use Asset, Accumulated Depreciation Finance lease right-of-use assets, net Finance Lease, Right-of-Use Asset Total lease right-of-use assets Leases, Right-Of-Use Asset Leases, Right-Of-Use Asset Operating leases Lessee, Operating Lease, Description [Abstract] Operating lease liabilities, current Operating Lease, Liability, Current Long-term operating lease liabilities Operating Lease, Liability, Noncurrent Total operating lease liabilities Operating Lease, Liability Finance Leases Lessee, Finance Lease, Description [Abstract] Finance lease liabilities, current Finance Lease, Liability, Current Finance lease liabilities, noncurrent Finance Lease, Liability, Noncurrent Total finance lease liabilities Finance Lease, Liability Total lease liabilities Leases, Liability Leases, Liability Related Party Transactions [Abstract] Schedule of related party transactions Schedule of Related Party Transactions [Table Text Block] Revenue from Contract with Customer [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Supply and Logistics Segment Supply And Logistics [Member] The segment of the entity of which operations generally consist of merchant-related activities, including the purchase of crude oil, natural gas liquids and natural gas at various locations and the resale or exchange of such products at various points along the distribution chain, the storage of inventory during contango market or seasonal storage of NGL and the transportation of crude oil and natural gas liquids, using various methods of transportation, from various delivery points, market hub locations or directly to end users. Transportation Segment Transportation [Member] The segment of the entity of which operations generally consist of fee-based activities associated with transporting crude oil and natural gas liquids on pipelines, gathering systems, trucks and barges. Facilities Segment Facilities [Member] The segment of the entity of which operations generally consist of fee-based activities associated with providing storage, terminalling and throughput services for crude oil, refined products, natural gas liquids and natural gas, as well as natural gas liquids fractionation and isomerization services and natural gas and condensate processing services. Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Crude oil transactions Crude Oil Transactions [Member] Crude Oil Transactions [Member] NGL and other transactions NGL And Other Transactions [Member] NGL And Other Transactions [Member] Total tariff activities Tariff Activities [Member] Tariff Activities [Member] Crude oil pipelines Tariff Activities, Crude Oil Pipelines [Member] Tariff Activities, Crude Oil Pipelines [Member] NGL pipelines Tariff Activities, NGL Pipelines [Member] Tariff Activities, NGL Pipelines [Member] Trucking Trucking [Member] Trucking [Member] Crude oil, NGL and other terminalling and storage Crude Oil, NGL, And Other Terminalling And Storage [Member] Crude Oil, NGL, And Other Terminalling And Storage [Member] NGL and natural gas processing and fractionation NGL And Natural Gas Processing And Fractionation [Member] NGL And Natural Gas Processing And Fractionation [Member] Rail load / unload Rail Load And Unload [Member] Rail Load And Unload [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Change in Contract Liabilities [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Beginning balance Contract with Customer, Liability Amounts recognized as revenue Contract with Customer, Liability, Revenue Recognized Additions Contract with Customer, Liability, Additions Amount of additions to obligation to transfer good or service to customer for which consideration from customer has been received or is due. Ending balance Schedule of lease costs and other lessee information Lease, Cost [Table Text Block] Lease Assets and Liabilities Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee Schedule of Operating Lease Maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of Finance Lease Maturity Finance Lease, Liability, Maturity [Table Text Block] Schedule of Lessor Future Revenues Maturity Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] Debt Disclosure [Abstract] Schedule of debt Schedule of Debt [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Pipeline revenues supported by minimum volume commitments and long-term capacity agreements Pipeline Revenues Supported By Minimum Volume Commitments And Long-Term Capacity Agreements [Member] Pipeline revenues supported by minimum volume commitments and long-term capacity agreements Long-term storage, terminalling and throughput agreement revenues Long-Term Storage, Terminalling And Throughput Agreements Revenues [Member] Long-Term Storage, Terminalling And Throughput Agreements Revenues [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Related Party Transactions Related Party Transactions Disclosure [Text Block] Income Statement [Abstract] Interest expense, capitalized interest Interest Costs Capitalized Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Consolidation and Presentation of Financial Statements [Table] Organization Consolidation and Presentation of Financial Statements [Table] Schedule detailing information related to organization, basis of accounting, or basis of presentation, used to prepare the financial reports of the entity. Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Consolidated Entity Excluding VIE Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] PAA Plains All American Pipeline L P [Member] Represents the information pertaining to Plains All American Pipeline, L.P. ("PAA"). GP LLC Plains All American G P L L C [Member] Represents the information pertaining to Plains All American GP LLC, ("GP LLC"), in which the reporting entity owns a managing member interest. AAP Plains Aap L P [Member] Represents information pertaining to Plains, AAP L.P (AAP). Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Organization and basis of presentation Organization and Basis of Presentation [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Ownership interest in the subsidiary Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest Ownership interest in the subsidiary (units) Subsidiary of Limited Liability Company or Limited Partnership Ownership Interest Units The number of units of the subsidiary owned by the limited partnership representing limited partner interests. Operating segments number Number of Operating Segments Deferred tax asset Deferred Income Tax Assets, Net Partners' Capital Notes [Abstract] Partners' Capital and Distributions [Table] Partners' Capital and Distributions [Table] Disclosure reflecting information pertaining to Partners' Capital and related distributions. Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Common Units and Series A Preferred Units Common Units And Series A Preferred Units [Member] Common Units And Series A Preferred Units [Member] Series B Preferred Units Series B Preferred Units [Member] Series B preferred units representing perpetual limited partner interests in the entity that rank pari passu with Series A preferred units and are not redeemable at the opiton of the holders under any circumstances. Partners' Capital and Distributions Partners Capital and Distribution [Line Items] No definition available. Noncontrolling interests in subsidiaries (percent) Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Earnings Per Share [Abstract] Net Income Per Class A Share Earnings Per Share [Text Block] Calculation of basic and diluted net income per Class A share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Class A Shares Shares Class A [Member] Represents the classification of shares representing limited partner interests in the company that are held by the public. Class A shareholders have equal voting rights with Class B shareholders and are entitled to receive distributions should distributions be paid by the company. Series A Preferred Units Seriesa Preferred Units [Member] Series A preferred units representing limited partner interests in the entity that rank pari passu with Series B preferred units, and senior to our common units and to each other classes or series of our equity securities with respect to distribution rights and rights upon liquidation and are convertible into common units by the holder or the entity under certain conditions. Common Units Common Units [Member] Common units representing limited partner interests in the entity. Schedule of activity for Class A shares, Class B shares and Class C shares Schedule of Stockholders Equity [Table Text Block] Schedule of distributions Distributions Made to Limited Partner, by Distribution [Table Text Block] Type of Arrangement and Non-arrangement Transactions [Axis] Type of Arrangement and Non-arrangement Transactions [Axis] Arrangements and Non-arrangement Transactions [Domain] Arrangements and Non-arrangement Transactions [Domain] Minimum Volume Commitments Minimum Volume Commitment Agreements [Member] Agreements that require counterparties to deliver, transport or throughput a minimum volume over an agreed upon period, some of which include make-up rights. Counterparty deficiencies Counterparty Deficiencies Amount associated with deficiencies by counterparties of their contractual minimum commitments. Contract liability, deferred revenue Counterparty deficiencies unbilled and uncollected Counterparty Deficiencies Unbilled And Uncollected Amount that has yet to be billed or collected as of the balance sheet date associated with deficiencies by counterparties of their contractual minimum commitments. Substantially all trade accounts receivable, net, maximum age of balances past their scheduled invoice date Trade Accounts Receivable Net Disclosure of Maximum Age of Balances Past Scheduled Invoice Date The maximum number of days past their scheduled invoice date for substantially all of the trade accounts receivable. Allowance for doubtful accounts receivable Allowance for Doubtful Accounts Receivable, Current Equity Method Investments and Joint Ventures [Abstract] Investments in Unconsolidated Entities Equity Method Investments and Joint Ventures Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivatives and Risk Management Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Document and Entity Information Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Emerging Growth Company Entity Emerging Growth Company Small Business Entity Entity Small Business Entity Common Stock, Shares Outstanding (shares) Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Lessor, Operating Leases Lessor, Operating Leases [Text Block] Lessee, Finance Leases Lessee, Finance Leases [Text Block] Lessee, Operating Leases Lessee, Operating Leases [Text Block] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Contracts with Customers, Assets and Liabilities Contract with Customer, Asset and Liability [Table Text Block] Remaining Performance Obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Statement Statement [Line Items] ASSETS Assets [Abstract] CURRENT ASSETS Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash, Current Trade accounts receivable and other receivables, net Receivables, Net, Current Inventory Inventory, Net Other current assets Other Assets, Current Total current assets Assets, Current PROPERTY AND EQUIPMENT Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Net OTHER ASSETS Other Assets, Noncurrent [Abstract] Goodwill Goodwill Investments in unconsolidated entities Equity Method Investments Linefill and base gas Linefill and Base Gas Crude oil and NGL linefill in pipelines, tanks and caverns as well as base gas in natural gas storage facilities that are owned by the entity. Linefill and base gas are intended for long-term use. Long-term inventory Inventory, Noncurrent Other long-term assets, net Other Assets, Noncurrent Total assets Assets LIABILITIES AND PARTNERS’ CAPITAL Liabilities and Equity [Abstract] CURRENT LIABILITIES Liabilities, Current [Abstract] Trade accounts payable Accounts Payable, Trade, Current Short-term debt Debt, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current LONG-TERM LIABILITIES Liabilities, Noncurrent [Abstract] Senior notes, net Senior Notes, Noncurrent Other long-term debt, net Other Long-term Debt, Noncurrent Other long-term liabilities and deferred credits Liabilities, Other than Long-term Debt, Noncurrent Total long-term liabilities Liabilities, Noncurrent COMMITMENTS AND CONTINGENCIES (NOTE 13) Commitments and Contingencies PARTNERS’ CAPITAL Partners' Capital, Including Portion Attributable to Noncontrolling Interest [Abstract] Class A shareholders (159,485,588 and 159,485,588 shares outstanding, respectively) Limited Partners' Capital Account Noncontrolling interests Partners' Capital Attributable to Noncontrolling Interest Total partners’ capital Partners' Capital, Including Portion Attributable to Noncontrolling Interest Total liabilities and partners’ capital Liabilities and Equity Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Offsetting Assets, Liabilities [Table] Offsetting Assets, Liabilities [Table] Disclosure of information about derivative and financial assets/ (liabilities) that are subject to offsetting, including enforceable master netting arrangements. Other current assets Other Current Assets [Member] Other long-term assets, net Other Noncurrent Assets [Member] Other long-term liabilities and deferred credits Other Noncurrent Liabilities [Member] Derivative and financial assets and liabilities subject to offsetting Offsetting Assets, Liabilities [Line Items] Netting Adjustment: Offsetting [Abstract] Derivative Asset Positions Offsetting Derivative Assets [Abstract] Gross Position - Asset Derivative Asset, Fair Value, Gross Asset Netting adjustment Derivative Asset, Fair Value, Gross Liability Cash collateral received Derivative Asset, Collateral, Obligation to Return Cash, Offset Net Position - Asset Derivative Asset Derivative Liability Positions Offsetting Derivative Liabilities [Abstract] Gross Position - Liability Derivative Liability, Fair Value, Gross Liability Netting adjustment Derivative Liability, Fair Value, Gross Asset Net Position - Liability Derivative Liability Operating cash flows for operating leases Operating Lease, Payments Financing cash flows for finance leases Finance Lease, Principal Payments Weighted-average remaining lease term (in years) Lease, Weighted Average Remaining Lease Term [Abstract] Lease, Weighted Average Remaining Lease Term [Abstract] Operating leases, weighted-average lease term Operating Lease, Weighted Average Remaining Lease Term Finance leases, weighted average lease term Finance Lease, Weighted Average Remaining Lease Term Weighted-average discount rate Leases, Weighted Average Discount Rate, Percent [Abstract] Leases, Weighted Average Discount Rate, Percent [Abstract] Operating leases, weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent Finance leases, weighted-average discount rate Finance Lease, Weighted Average Discount Rate, Percent Schedule of Calculation of Basic and Diluted Net Income Per Class A Share [Table] Schedule of Calculation of Basic and Diluted Net Income Per Class A Share [Table] Schedule reflecting the calculation of basic and diluted net income per share. Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum Maximum [Member] Net Income Per Class A Share Basic and Diluted Net Income Per Class A Share [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Dilutive LTIP awards (shares), less than Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Basic and Diluted Net Income per Class A Share Earnings Per Share, Basic [Abstract] Net income attributable to PAGP Net Income (Loss) Attributable to Parent Basic and diluted weighted average Class A shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Basic and diluted net income per Class A share (in dollars per share) Earnings Per Share, Basic and Diluted Inventory, Linefill and Base Gas and Long-term Inventory Schedule of inventory, linefill and base gas and long-term inventory Schedule of Inventory Linefill and Base Gas and Long Term Inventory [Table Text Block] Tabular disclosure of the carrying amount as of the balance sheet date of inventory, linefill and base gas and long-term inventory. This may include, but is not limited to, the volumes, unit of measure, total value, and price per unit of each of the major classes of inventory. Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Organization and Basis of Consolidation and Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Schedule of goodwill by segment and changes during the period Schedule of Goodwill [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivatives in Hedging Relationships Designated as Hedging Instrument [Member] Derivatives Not Designated as a Hedge Not Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Commodity Derivatives Commodity Contract [Member] Foreign Currency Derivatives Foreign Exchange Contract [Member] Preferred Distribution Rate Reset Option Embedded Derivative Financial Instruments [Member] Interest Rate Derivatives Interest Rate Contract [Member] Derivative assets and liabilities Derivatives, Fair Value [Line Items] Asset Derivatives Fair Value Liability Derivatives Fair Value Net loss deferred in AOCI Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Net loss expected to be reclassified to earnings in the next twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Net unrealized gain/(loss) recognized in net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Schedule of Investments in Unconsolidated Entities [Table] Schedule of Equity Method Investments [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Gain on investment in unconsolidated entities Gain on Investment In Unconsolidated Entities [Member] Gain on Investment In Unconsolidated Entities [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Capline pipeline system Capline Pipeline Company LLC Capline Pipeline Company LLC [Member] Capline Pipeline Company LLC [Member] Undivided joint interest in Capline pipeline system Undivided Interest [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Advantage Pipeline Holdings LLC Advantage Pipeline, LLC [Member] Advantage Pipeline, LLC [Member] BridgeTex Pipeline Company, LLC BridgeTex Pipeline Company, LLC [Member] BridgeTex Pipeline Company, LLC [Member] Cactus II Pipeline LLC CactusIIPipelineLLC [Member] Cactus II Pipeline LLC Caddo Pipeline LLC Caddo Pipeline Llc [Member] Caddo Pipeline LLC, a crude oil pipeline company. Cheyenne Pipeline LLC Cheyenne Pipeline Llc [Member] Cheyenne Pipeline LLC. Diamond Pipeline LLC Diamond Pipeline Llc [Member] Diamond Pipeline LLC, a crude oil pipeline company. Eagle Ford Pipeline LLC Eagle Ford Pipeline L L C [Member] Eagle Ford Pipeline LLC, a crude oil pipeline company. Eagle Ford Terminals Corpus Christi LLC Eagle Ford Terminals Corpus Christi Llc [Member] Eagle Ford Terminals Corpus Christi LLC, a crude oil terminal and dock company. Midway Pipeline LLC Midway Pipeline LLC [Member] Midway Pipeline LLC [Member] Saddlehorn Pipeline Company, LLC Saddlehorn Pipeline Company Llc [Member] Saddlehorn Pipeline Company LLC, a crude oil pipeline company. Settoon Towing, LLC Settoon Towing L L C [Member] Settoon Towing, LLC (Settoon Towing), a barge transportation services company. STACK Pipeline LLC STACK Pipeline LLC [Member] STACK Pipeline LLC [Member] White Cliffs Pipeline, LLC White Cliffs Pipeline Llc [Member] White Cliffs Pipeline, LLC, a crude oil pipeline company. Wink to Webster Pipeline LLC (“W2W Pipeline”) Wink to Webster Pipeline LLC [Member] Wink to Webster Pipeline LLC [Member] Investments in Unconsolidated Entities Schedule of Equity Method Investments [Line Items] Percentage of Capline pipeline system owned Noncash or Part Noncash Acquisition, Interest Acquired Ownership interest in unconsolidated entity Equity Method Investment, Ownership Percentage Investments in unconsolidated entities Undivided joint interest ownership percentage Undivided Joint Interest Ownership Percentage Undivided Joint Interest Ownership Percentage Carrying value of undivided joint interest Fair value of investment in unconsolidated entity Equity Method Investments, Fair Value Disclosure Gain from remeasurement to fair value of retained investment Deconsolidation, Revaluation of Retained Investment, Gain (Loss), Amount Remainder of 2019 Lessor, Operating Lease, Payments to be Received, Remainder of Fiscal Year 2020 Lessor, Operating Lease, Payments to be Received, Two Years 2021 Lessor, Operating Lease, Payments to be Received, Three Years 2022 Lessor, Operating Lease, Payments to be Received, Four Years 2023 Lessor, Operating Lease, Payments to be Received, Five Years Thereafter Lessor, Operating Lease, Payments to be Received, Thereafter Segment Reporting [Abstract] Segment financial data Schedule of Segment Reporting Information, by Segment [Table Text Block] Reconciliation of segment Adjusted EBITDA to net income attributable to PAGP Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Inventory, Linefill and Base Gas and Long-term Inventory Inventory Linefill and Base Gas and Long Term Inventory Disclosure [Text Block] The complete disclosure related to inventory, linefill and base gas and long-term inventory. This may include, but is not limited to, the basis of stating inventory, linefill, and base gas and long-term inventory, the method of determining inventory, linefill and base gas and long-term inventory cost, the major classes of inventory, linefill and base gas and long-term inventory, and the nature of the cost elements included in inventory, linefill and base gas and long-term inventory. If inventory, linefill and base gas and long-term inventory is stated above cost, accrued net losses on firm purchase commitments for inventory, linefill and base gas and long-term inventory and losses resulting from valuing inventory, linefill and base gas and long-term inventory at the lower-of-cost-or-market may also be included. New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Net lease right-of-use assets recognized upon adoption of Topic 842 Lease liabilities recognized upon adoption of Topic 842 Other Product and Service, Other [Member] Intersegment Intersegment Eliminations [Member] Revenues from contracts with customers Total revenues Revenues Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Partner Capital Components [Axis] Partner Capital Components [Axis] Partner Capital Components [Domain] Partner Capital Components [Domain] Derivative Instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member] Translation Adjustments Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Other AOCI, Other, Including Portion Attributable to Noncontrolling Interest [Member] AOCI, Other, Including Portion Attributable to Noncontrolling Interest [Member] Total AOCI Including Portion Attributable to Noncontrolling Interest [Member] Changes in Accumulated Other Comprehensive Income/(Loss) AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Balance at beginning of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Reclassification adjustments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Unrealized gain/(loss) on hedges Currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Other Other Comprehensive Income, Other, Net of Tax Total period activity Other Comprehensive Income (Loss), Net of Tax Balance at end of period Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Recent Accounting Pronouncements/Accounting Standards Updates Adopted During the Period New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Minimum Minimum [Member] Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Agreement To Transport Crude Oil On Pipeline Of Equity Method Investee Agreement To Transport Crude Oil On Pipeline Of Equity Method Investee [Member] An agreement to transport crude oil on a pipeline that is owned by an equity method investee. Class C Shares Shares Class C [Member] Class C shares represent a non-economic limited partner interest that provides the holder the right to vote in elections of eligible directors together with the holders of Class A and Class B shares. Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Principal Owner Principal Owner [Member] Equity Method Investee Equity Method Investee [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Shares owned Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest, Units Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest, Units Limited partner interest Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Revenues from related parties Revenue from Related Parties Purchases and related costs from related parties Related Party Transaction, Purchases from Related Party Trade accounts receivable and other receivables, net from related parties Due from Related Parties, Current Trade accounts payable to related parties Due to Related Parties, Current Ownership interest in unconsolidated entity Statement of Partners' Capital [Abstract] ASU 2017-05 Accounting Standards Update 2017-05 [Member] Partner Type [Axis] Partner Type [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Limited Partners Limited Partner [Member] Noncontrolling Interests Noncontrolling Interest [Member] Increase (Decrease) in Partners' Capital Increase (Decrease) in Partners' Capital [Roll Forward] Beginning balance Impact of adoption of ASU 2017-05 Cumulative Effect of New Accounting Principle in Period of Adoption Beginning balance, adjusted balance Partners' Capital, Adjusted Balance Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Distributions (Note 9) Partners' Capital Account, Distributions Other comprehensive income/(loss) Equity-indexed compensation expense Partners' Capital Account, Unit-based Compensation Other Partners' Capital, Other Ending balance Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] A table or schedule providing information pertaining to short-term and long-term debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] GO Zone term loans GO Zone Term Loans [Member] GO Zone Term Loans [Member] 5.75% Senior Notes Due In January 2020 Senior Notes Due In January2020 At5.75 Percent [Member] Represents the 5.75 percent senior notes, which are due in January 2020. 2.60% Senior Notes Due In December 2019 Senior Notes Due In December2019 At2.60 Percent [Member] Represents the 2.60 percent senior notes, which are due in December 2019. Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Other Other Debt [Member] Other types of debt not specifically identified. Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior notes Senior Notes [Member] Term loan Term Loan [Member] Term Loan [Member] Other Debt Debt Instrument [Line Items] Short-term debt: Short-term Debt [Abstract] Total short-term debt Long-term debt: Long-term Debt, Unclassified [Abstract] PAA senior notes, net of unamortized discounts and debt issuance costs of $57 and $59, respectively (1) (2) Total long-term debt Long-term Debt and Capital Lease Obligations Unamortized discounts and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Weighted average interest rate, long-term Long-term Debt, Weighted Average Interest Rate, at Point in Time Debt issuance costs Debt Issuance Costs, Net Total debt Debt and Capital Lease Obligations Debt instrument face value Debt Instrument, Face Amount Stated percentage Debt Instrument, Interest Rate, Stated Percentage Debt instrument fair value Debt Instrument, Fair Value Disclosure Investments in and summarized financial information for unconsolidated entities accounted for under the equity method of accounting Equity Method Investments [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value Measures Fair Value, Measurements, Recurring [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Recurring Fair Value Measurements Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Total net derivative asset/(liability) Derivative, Fair Value, Net Rollforward of Level 3 Net Asset/(Liability) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Beginning Balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Net gains/(losses) for the period included in earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Derivatives entered into during the period Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis Unobservable Inputs Reconciliation, Derivatives Entered Into Amount of derivatives entered into classified as a derivative asset (liability) after deduction of derivative asset (liability), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Ending Balance Change in unrealized gains/(losses) included in earnings relating to Level 3 derivatives still held at the end of the period Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss) Lessee, Lease, Description [Table] Lessee, Lease, Description [Line Items] Term of lease Lessee, Leases, Term Of Contract Lessee, Leases, Term Of Contract Extension option term Lessee, Leases, Renewal Term Lessee, Leases, Renewal Term Obligations for leases that have not yet commenced Operating And Finance Lease, Lease Not Yet Commenced, Expense, Payments Due Operating And Finance Lease, Lease Not Yet Commenced, Expense, Payments Due Leases not yet commenced, term of contract Lessee, Operating and Finance Leases, Lease Not yet Commenced, Term of Contract Term of lessee's operating and finance leases not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D represents reported fact of one year, five months, and thirteen days. Term of contract, facilities Lessor, Operating Lease, Term of Contract Supply and Logistics Transportation Facilities REVENUES Revenues [Abstract] COSTS AND EXPENSES Costs and Expenses [Abstract] Purchases and related costs Cost of Goods and Services Sold Field operating costs Operating Costs and Expenses General and administrative expenses General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization (Gains)/losses on asset sales and asset impairments, net Gain (Loss) on Sale of Assets and Asset Impairment Charges Total costs and expenses Costs and Expenses OPERATING INCOME Operating Income (Loss) OTHER INCOME/(EXPENSE) Nonoperating Income (Expense) [Abstract] Equity earnings in unconsolidated entities Income (Loss) from Equity Method Investments Gain on investment in unconsolidated entities (Note 7) Gain Loss On Investment In Unconsolidated Entities Amount of gain (loss) (i) from remeasurement to fair value of retained investment in former subsidiary and group of assets constituting business activity deconsolidated and derecognized and/or (ii) on sale or disposal of an equity method investment. Interest expense (net of capitalized interest of $11 and $6, respectively) Interest Expense Other income/(expense), net Other Nonoperating Income (Expense) INCOME BEFORE TAX Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Current income tax expense Current Income Tax Expense (Benefit) Deferred income tax expense Deferred Income Tax Expense (Benefit) NET INCOME Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest NET INCOME ATTRIBUTABLE TO PAGP BASIC AND DILUTED NET INCOME PER CLASS A SHARE (in dollars per share) BASIC AND DILUTED WEIGHTED AVERAGE CLASS A SHARES OUTSTANDING (in shares) Operating lease cost Operating Lease, Cost Short-term lease cost Short-term Lease, Cost Other Other Lease Cost Other Lease Cost Total lease cost Lease, Cost Debt Debt Disclosure [Text Block] Credit agreements and PAA commercial paper program Line Of Credit And Commercial Paper [Member] Represents information pertaining to the line of credit and commercial paper agreement entered into by the entity. Total borrowings Proceeds from Issuance of Debt Total repayments Repayments of Debt Outstanding letters of credit Letters of Credit Outstanding, Amount Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] Distributions to Class A shareholders Limited Partners' Capital Account, Distribution Amount Distribution per Class A share, paid (usd per share) Distribution Made to Limited Partner, Distributions Paid, Per Unit Derivative [Table] Derivative [Table] 8 forward starting interest rate swaps (30-year), 2.83% Eight Forward Starting Thirty Year Interest Rate Swaps2.83 Percent [Member] Eight forward starting 30-year interest rate swaps to hedge the underlying benchmark interest rate related to anticipated interest payments, with an average fixed rate of 2.83 percent. 8 forward starting interest rate swaps (30-year), 3.06% Eight Forward Starting Thirty Year Interest Rate Swaps 3.06 Percent [Member] Eight Forward Starting Thirty Year Interest Rate Swaps 3.06 Percent [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash flow hedge Cash Flow Hedging [Member] Derivatives and Risk Management Activities Derivative [Line Items] Interest Rate Risk Hedging Interest Rate Derivatives [Abstract] Number of interest rate derivatives Number of Interest Rate Derivatives Held Term of derivative contract Derivative, Term of Contract Notional amount of derivatives Derivative, Notional Amount Average rate locked (percent) Derivative, Average Fixed Interest Rate Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Shares outstanding Limited Partners' Capital Account [Line Items] Shares outstanding (shares) Limited Partners' Capital Account, Units Outstanding Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Forward exchange contracts that exchange CAD For USD maturing in 2019 Foreign Exchange Forward Contracts That Exchange Canadian Dollars For US Dollars At Average Rate Disclosed Maturing in 2019 [Member] Foreign Exchange Forward Contracts That Exchange Canadian Dollars For US Dollars At Average Rate Disclosed Maturing in 2019 [Member] Forward exchange contracts that exchange USD for CAD maturing in 2019 Foreign Exchange Forward Contracts That Exchange U S Dollars For Canadian Dollars At Average Rate Disclosed Maturing In 2019 [Member] Foreign Exchange Forward Contracts That Exchange U S Dollars For Canadian Dollars At Average Rate Disclosed Maturing In 2019 [Member] Currency Exchange Rate Risk Hedging: Foreign Currency Derivatives [Abstract] Average exchange rate (cad per usd) Derivative, Average Forward Exchange Rate Statement of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Reconciliation of net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] (Gains)/losses on asset sales and asset impairments, net Equity-indexed compensation expense Allocated Share-based Compensation Expense Deferred income tax expense Loss on foreign currency revaluation Foreign Currency Transaction Gain (Loss), before Tax Change in fair value of Preferred Distribution Rate Reset Option (Note 10) Embedded Derivative, Gain (Loss) on Embedded Derivative, Net Equity earnings in unconsolidated entities Distributions on earnings from unconsolidated entities Proceeds from Equity Method Investment, Distribution Gain on investment in unconsolidated entities (Note 7) Other Other Noncash Income (Expense) Changes in assets and liabilities Increase (Decrease) in Operating Capital Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Investments in unconsolidated entities Capital Contributions to Equity Method Investees Cash outflow for capital contributions subsequent to the initial purchase of interest in equity method investments. Additions to property, equipment and other Payments to Acquire Property, Plant, and Equipment Proceeds from sales of assets Proceeds from Sale of Productive Assets Cash paid for purchases of linefill and base gas Cash Paid Related to Purchases of Linefill and Base Gas The cash outflow associated with the purchase of linefill and base gas. Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Net repayments under PAA commercial paper program (Note 8) Proceeds from (Repayments of) Commercial Paper Net borrowings under PAA senior unsecured revolving credit facility (Note 8) Proceeds from (Repayments of) Lines of Credit Net repayments under PAA senior secured hedged inventory facility (Note 8) Net Proceeds from (Repayments of) Hedged Inventory Facility The net cash inflow (outflow) due to borrowings (repayments) on the hedged inventory facility. Distributions paid to Class A shareholders (Note 9) Distribution Made to Limited Partner, Cash Distributions Paid Distributions paid to noncontrolling interests (Note 9) Payments of Ordinary Dividends, Noncontrolling Interest Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Effect of translation adjustment Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Net increase/(decrease) in cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash and cash equivalents and restricted cash, beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents and restricted cash, end of period Cash paid for: Supplemental Cash Flow Information [Abstract] Interest, net of amounts capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes, net of amounts refunded Income Taxes Paid, Net Reconciliation from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Unallocated Segment Reconciling Items [Member] Segment Reporting, Reconciling Item from Segments to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Segment Adjusted EBITDA Segment Adjusted EBITDA Revenues and equity earnings in unconsolidated entities less (a) purchases and related costs, (b) field operating costs and (c) segment general and administrative expenses, plus the entity’s proportionate share of the depreciation and amortization expense and gains and losses on significant asset sales of unconsolidated entities, and further adjusted for certain selected items including (i) gains or losses on derivative on derivative instruments that are related to underlying activities in another period (or the reversal of such adjustments from a prior period), gains and losses on derivatives that are related to investing activities (such as the purchase of linefill) and inventory valuation adjustments, as applicable, (ii) long-term inventory costing adjustments, (iii) charges for obligations that are expected to be settled with the issuance of equity instruments, (iv) amounts related to deficiencies associated with minimum volume commitments, net of applicable amounts subsequently recognized into revenue and (v) other items that the Chief Operating Decision Maker believes are integral to understand the entity’s core segment operating performance. Adjustments: Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract] Depreciation and amortization of unconsolidated entities Depreciation And Amortization Of Unconsolidated Entities The reporting entity’s proportionate share of depreciation and amortization expense and gains or losses on significant asset sales of unconsolidated entities. Gains from derivative activities net of inventory valuation adjustments Gains (Losses) From Derivative Activities, Net of Inventory Valuation Adjustments Gains (losses) related to derivative instruments for which the underlying transaction does not occur in the current period and on derivatives that are related to investing activities, such as the purchase of linefill. Also includes the impact of corresponding inventory valuation adjustments, as applicable. Long-term inventory costing adjustments Long-Term Inventory Costing Adjustments Includes the impact of changes (resulting from fluctuations in market prices) in the average cost of crude oil and NGL inventory that is comprised of minimum working inventory requirements in third-party assets and other working inventory that is needed for the entity’s commercial operations which is considered necessary to conduct the entity’s operations and which the entity intends to carry for the foreseeable future, as well as writedowns of such inventory that result from price declines. Deficiencies under minimum volume commitments, net Deficiencies Under Minimum Volume Commitments, Net Includes the impact of amounts billed to counterparties for their deficiency obligation, net of applicable amounts subsequently recognized into revenue. Certain agreements require counterparties to deliver, transport or throughput a minimum volume over an agreed upon period. Substantially all of such agreements were entered into with counterparties to economically support the return on the reporting entity's capital expenditure necessary to construct the related asset. Some of these agreements include make-up rights if the minimum volume is not met. A receivable from the counterparty is recorded in the period that services are provided or when the transaction occurs, including amounts for deficiency obligations from counterparties associated with minimum volume commitments. If a counterparty has a make-up right associated with a deficiency, the revenue attributable to the counterparty’s make-up right is deferred and is subsequently recognized at the earlier of when the deficiency volume is delivered or shipped, when the make-up right expires or when it is determined that the counterparty’s ability to utilize the make-up right is remote. Equity-indexed compensation expense Equity Indexed Compensation Expense Awards That Will Or May Be Settled In Units Includes equity-indexed compensation expense associated with awards that will or may be settled in units. Net loss on foreign currency revaluation Net Gain (Loss) On Foreign Currency Revaluation Includes gains and losses from the revaluation of foreign currency transactions and monetary assets and liabilities. Unallocated general and administrative expenses Depreciation and amortization Gains/(losses) on asset sales and asset impairments, net Gain on investment in unconsolidated entities Interest expense, net Income tax expense Income Tax Expense (Benefit) Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill Goodwill [Line Items] Changes in goodwill Goodwill [Roll Forward] Beginning Balance Foreign currency translation adjustments Goodwill, Foreign Currency Translation Gain (Loss) Ending Balance Class B Shares Shares Class B [Member] Represents the classification of shares representing limited partner interests in the company that are not held by the public. Class B shareholders have equal voting rights with Class A shareholders but are not entitled to receive distributions. Activity for Class A shares, Class B shares and Class C shares Balance, beginning of period (shares) Exchange Right exercises (shares) Limited Partners Capital Account Shares Issued (Exchanged) in Exchange Right Exercises Represents the number of shares issued (exchanged) in connection with Exchange Right exercises. Redemption Right exercises (shares) Limited Partners Capital Account, Shares Issued (Redeemed) in Redemption Right Exercises Limited Partners Capital Account, Shares Issued (Redeemed) in Redemption Right Exercises Issuance of Series A preferred units by a subsidiary (shares) Partners' Capital Account, Units, Increase from Subsidiary Preferred Unit Issuance Partners' Capital Account, Units, Increase from Subsidiary Preferred Unit Issuance Other (shares) Partners' Capital, Units, Other Changes in the number of units outstanding included in the statement of changes in partners' capital which are not separately disclosed or provided for elsewhere in the taxonomy. Balance, end of period (shares) Statement of Comprehensive Income [Abstract] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to PAGP Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net long position associated with crude oil purchases Net Long Position On Crude Oil Derivative Contracts [Member] Represents the derivative instruments utilized to hedge risk associated with crude oil purchases. Net short time spread position hedging anticipated crude oil lease gathering purchases Net Short Time Spread Position On Anticipated Crude Oil Lease Gathering Purchase Contracts [Member] Represents the derivative instruments utilized to hedge anticipated crude oil lease gathering purchases. Crude oil basis spread position Crude Oil Grade Basis Position [Member] Represents the derivative instruments that hedge crude oil purchases based on grade basis differentials. Net short position related to anticipated net sales of crude oil and NGL inventory Net Short Position Contracts Related To Anticipated Net Sales Of Inventory [Member] Represents the derivative instruments in a net short position related to anticipated net sales of crude oil and NGL inventory. Positions hedging risk of not utilizing storage capacity Positions Hedging Risk of Not Utilizing Storage Capacity [Member] Positions Hedging Risk of Not Utilizing Storage Capacity [Member] PLA short position consisting of crude oil futures Pipeline Loss Allowance Net Short Position Consisting of Crude Oil Futures [Member] Represents the derivative instruments in a net short position consisting of crude oil futures related to pipeline loss allowance. PLA long call option position Pipeline Loss Allowance Oil Long Call Option [Member] Represents the derivative instruments in a long call option position related to pipeline loss allowance for crude oil. Long natural gas position for natural gas purchases and operational needs Long Position On Natural Gas Contracts [Member] Represents derivative instruments consisting of long natural gas position related to purchase of natural gas. Short propane position related to subsequent sale of products Short Propane Position Contracts Related To Subsequent Sale Of Product [Member] Represents the derivative instruments in a short position for propane that hedges the subsequent sale of products derived from our natural gas processing and NGL fractionation activities. Short butane position related to subsequent sale of products Short Butane Position Contracts Related To Subsequent Sale Of Product [Member] Represents the derivative instruments in a short position for butane that hedges the subsequent sale of products derived from our natural gas processing and NGL fractionation activities. Short WTI position related to subsequent sale of products Short W T I Position Contracts Related To Subsequent Sale Of Product [Member] Represents the derivative instruments in a short position for WTI that hedges the subsequent sale of products derived from our natural gas processing and NGL fractionation activities. Net long position related to anticipated sales of specification products (put options) Net Long Position Contracts Related To Anticipated Sales Of Specification Products [Member] Net Long Position Contracts Related To Anticipated Sales Of Specification Products [Member] Long power position for power supply requirements Long Power Position For Power Supply Requirements Contracts [Member] Represents the derivative instruments consisting of long power positions which hedge a portion of power supply requirements. Commodity Price Risk Hedging: Price Risk Derivatives [Abstract] Derivative position notional amount (in barrels or Mcf) Derivative, Nonmonetary Notional Amount, Volume Derivative position notional amount (in megawatt hours) Derivative, Nonmonetary Notional Amount, Energy Measure Trade accounts receivable arising from revenues from contracts with customers Contract with Customer, Asset, Net, Current Other trade accounts receivables and other receivables Accounts and Other Receivables, Net, Current Impact due to contractual rights of offset with counterparties Contract With Customer, Contractual Rights Of Offset With Counterparties Amount of contractual rights of offset with counterparties that reduces the entity's right to consideration in exchange for good or service transferred to customer. Trade accounts receivable and other receivables, net Loss Contingencies [Table] Loss Contingencies [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent event Subsequent Event [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Line 901 Incident Line901 Incident [Member] Represents information pertaining to the crude oil release from the Las Flores to Gaviota Pipeline in Santa Barbara County, California. Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] May 2016 Indictment Indictment In California Superior Court Santa Barbara County [Member] Indictment filed in California Superior Court, Santa Barbara County, with alleged violations of California law. Class Action Lawsuits Class Action Lawsuits [Member] Represents information related to class action lawsuits filed against the company. Securities Law Class Action Lawsuits Securities Law Class Action Lawsuits [Member] Represents information related to securities law class action lawsuits filed against the company. Unitholder Derivative Lawsuits Unitholder Derivative Lawsuits [Member] Represents information related to unitholder derivative lawsuits filed against the company. Trade accounts receivable and other receivables, net Trade Accounts Receivable And Other Receivables [Member] Primary financial statement caption encompassing trade accounts receivable and other receivables. Legal, Environmental or Regulatory Matters Loss Contingencies [Line Items] Estimated undiscounted reserve for environmental liabilities Accrual for Environmental Loss Contingencies, Gross Estimated undiscounted reserve for environmental liabilities, short-term Accrued Environmental Loss Contingencies, Current Estimated undiscounted reserve for environmental liabilities, long-term Accrued Environmental Loss Contingencies, Noncurrent Amounts probable of recovery under insurance and from third parties under indemnification agreements Recorded Third-Party Environmental Recoveries Receivable Estimated size of release (in bbl) Estimated Size of Release Represents the estimated size of the pipeline release. Estimated size of release to reach Pacific Ocean (in bbl) Estimated Size Of Release To Reach Body Of Water Estimated Size Of Release To Reach Body Of Water Number of employees charged Number of Employees Charged in Indictment Number of the entity's employees charged pursuant to an indictment. Total counts included in the indictment Indictment, Total Number of Counts Total number of counts included in the indictment. Number of counts dismissed Indictment, Total Number of Counts Dismissed Indictment, Total Number of Counts Dismissed Number of felony charges dismissed Indictment, Number of Felony Charges Dismissed Indictment, Number of Felony Charges Dismissed Number of felony charges found guilty Indictment, Number of Felony Charges, Guilty Verdict Indictment, Number of Felony Charges, Guilty Verdict Number of misdemeanor charges found guilty Indictment, Number of Misdemeanor Charges, Guilty Verdict Indictment, Number of Misdemeanor Charges, Guilty Verdict Number of misdemeanor charges found guilty, reporting Indictment, Number of Misdemeanor Charges, Guilty Verdict, Reporting Count Indictment, Number of Misdemeanor Charges, Guilty Verdict, Reporting Count Number of misdemeanor charges found guilty, strict liability discharge Indictment, Number of Misdemeanor Charges, Guilty Verdict, Strict Liability Discharge Count Indictment, Number of Misdemeanor Charges, Guilty Verdict, Strict Liability Discharge Count Number of misdemeanor charges found guilty, strict liability animal takings Indictment, Number of Misdemeanor Charges, Guilty Verdict, Strict Liability Animal Takings Count Indictment, Number of Misdemeanor Charges, Guilty Verdict, Strict Liability Animal Takings Count Number of misdemeanor charges not guilty, strict liability animal takings Indictment, Number of Misdemeanor Charges, Not Guilty Verdict, Strict Liability Animal Takings Count Indictment, Number of Misdemeanor Charges, Not Guilty Verdict, Strict Liability Animal Takings Count Number of charges jury deadlocked Indictment, Total Number of Counts, Jury Deadlocked Indictment, Total Number of Counts, Jury Deadlocked Number of charges jury deadlocked, felony discharges Indictment, Total Number of Counts, Jury Deadlocked, Felony Discharge Count Indictment, Total Number of Counts, Jury Deadlocked, Felony Discharge Count Number of charges jury deadlocked, strict liability animal takings Indictment, Total Number of Counts, Jury Deadlocked, Strict Liability Animal Takings Count Indictment, Total Number of Counts, Jury Deadlocked, Strict Liability Animal Takings Count Number of misdemeanor charges dropped Indictment, Number of Misdemeanor Charges Dropped Indictment, Number of Misdemeanor Charges Dropped Fines or penalties assessed Loss Contingency Penalty or Fine Assessed Represents penalty or fine assessed on the entity in connection with an environmental matter. Number of cases filed during the period Loss Contingency, New Claims Filed, Number Number of cases consolidated into a single proceeding Loss Contingency Number Of Cases Consolidated Into Single Proceeding Represents the total number of initially separate claims consolidated into a single proceeding. Aggregate total estimated costs Loss Contingency, Estimate of Possible Loss Recoveries from insurance carriers Loss Contingency, Receivable, Proceeds Total release costs probable of recovery Third Party Environmental Recoveries Received and Receivable Total third-party recoveries related to environmental remediation obligations, including amounts received to date and estimated amounts recoverable. Summary of open derivative positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of terms of outstanding interest rate derivatives Schedule of Derivative Instruments [Table Text Block] Impact of derivatives recognized in earnings Derivative Instruments, Gain (Loss) [Table Text Block] Summary of derivative assets and liabilities on Condensed Consolidated Balance Sheets on a gross basis Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of net broker receivable/(payable) Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block] Schedule of derivative financial assets that are subject to offsetting, including enforceable master netting arrangements Offsetting Assets [Table Text Block] Schedule of derivative financial liabilities that are subject to offsetting, including enforceable master netting arrangements Offsetting Liabilities [Table Text Block] Net deferred gain/(loss) recognized in AOCI for derivatives Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of derivative financial assets and liabilities accounted for at fair value on a recurring basis, by level within the fair value hierarchy Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Reconciliation of changes in fair value of derivatives classified as Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Transaction Type [Axis] Transaction Type [Axis] Transaction [Domain] Transaction [Domain] Exchange Traded Exchange Traded [Member] Offsetting Assets, Liabilities [Line Items] Initial margin Initial Margin The amount of cash or securities required by a broker or counterparty as security for a trading or derivatives securities position. Variation margin returned Variation Margin Posted Returned Cash posted by (returned to) the reporting entity to (from) a broker or counterparty to comply with initial margin requirements. Letters of credit Net broker payable Cash and cash equivalents Total cash and cash equivalents and restricted cash Revenues and Accounts Receivable Revenue from Contract with Customer [Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Supply and Logistics segment revenues Sales And Related Revenues [Member] Revenue from the sale of crude oil, NGL and natural gas during the period. Field operating costs Field Operating Costs [Member] Costs related to site and field operations during the period. Interest expense, net Interest Expense [Member] Other income/(expense), net Other Nonoperating Income (Expense) [Member] Impact of derivative activities recognized in earnings Derivative Instruments, Gain (Loss) [Line Items] Total gain/(loss) on derivatives recognized in net income Derivative, Gain (Loss) on Derivative, Net Operating Operating Lease Liabilities, Payments Due [Abstract] Remainder of 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total Lessee, Operating Lease, Liability, Payments, Due Less: Present value discount Lessee, Operating Lease, Liability, Undiscounted Excess Amount Lease liabilities Finance Finance Lease Liabilities, Payments, Due [Abstract] Remainder of 2019 Finance Lease, Liability, Payments, Remainder of Fiscal Year 2020 Finance Lease, Liability, Payments, Due Year Two 2021 Finance Lease, Liability, Payments, Due Year Three 2022 Finance Lease, Liability, Payments, Due Year Four 2023 Finance Lease, Liability, Payments, Due Year Five Thereafter Finance Lease, Liability, Payments, Due after Year Five Total Finance Lease, Liability, Payments, Due Less: Present value discount Finance Lease, Liability, Undiscounted Excess Amount Lease liabilities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Operating Segments, Before Intersegment Adjustment Operating Segments, Before Intersegment Adjustment [Member] Operating Segments, Before Intersegment Adjustment [Member] Intersegment Adjustment Eliminations And Reconciling Items [Member] Adjustment to reconcile revenues from external customers as presented to the Chief Operating Decision Maker to that presented on the statement of operations. Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Revenues: Segment Reporting Information, Revenue for Reportable Segment [Abstract] Revenues Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments [Abstract] Segment Adjusted EBITDA Maintenance capital Maintenance Capital Capital expenditures for the replacement of partially or fully depreciated assets in order to maintain the operating and/or earnings capacity of the company's existing assets. Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Public Public Unit Holders [Member] Public Unit Holders [Member] AAP Distribution Type [Axis] Distribution Type [Axis] Distribution Type [Domain] Distribution Type [Domain] Cash Distributions Cash Distribution [Member] Preferred unit distribution amount Dividends, Preferred Stock Preferred unit distribution amount (in dollars per unit) Preferred Stock, Dividends, Per Share, Cash Paid Amount accrued to distributions payable Dividends Payable Distributions to common unitholders Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Distributions to PAGP SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries Total distributions paid Distributions per common unit, paid (usd per unit) Operating Segments Segment Reporting Disclosure [Text Block] Inventory, Current [Table] Inventory, Current [Table] Inventory [Axis] Inventory [Axis] Inventory [Domain] Inventory [Domain] Crude oil Crude Oil [Member] NGL Natural Gas Liquids [Member] Natural gas Natural Gas [Member] Other Other Inventory [Member] Category of inventory not separately disclosed. Inventory [Line Items] Inventory [Line Items] Inventory by category Inventory Disclosure [Abstract] Total Inventory, Current and Noncurrent This element represents the aggregate of current and non-current inventory, including linefill and base gas. Inventory, Volumes (in barrels or in Mcf) Inventory, Volumes Current The volume of current inventory as of the balance sheet date. Linefill and base gas, Volumes (in barrels or in Mcf) Inventory, Volumes Linefill and Base Gas The volume of linefill and base gas inventory as of the balance sheet date. Long-term inventory, Volumes (in barrels or in Mcf) Inventory, Volumes, Noncurrent The volume of noncurrent inventory as of the balance sheet date. Inventory (Price/Unit of measure) Inventory, Weighted Average Price Per Unit, Current The weighted-average price per unit of current inventory. Linefill and base gas (Price/Unit of measure) Inventory, Weighted Average Price Per Unit Linefill and Base Gas The weighted-average price per unit of linefill and base gas inventory. Long-term inventory (Price/Unit of measure) Inventory, Weighted Average Price Per Unit Noncurrent The weighted-average price per unit of noncurrent inventory. Partners' Capital and Distributions Partners' Capital Notes Disclosure [Text Block]