Hedging Designation [Domain] Hedging Designation [Domain] Cash paid for: Supplemental Cash Flow Information [Abstract] 8 forward starting interest rate swaps (30-year), 0.73% Eight Forward Starting Thirty Year Interest Rate Swaps 0.73 Percent [Member] Eight Forward Starting Thirty Year Interest Rate Swaps 0.73 Percent Transportation 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. Estimated undiscounted reserve for environmental liabilities, long-term Accrued Environmental Loss Contingencies, Noncurrent Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] NET INCOME/(LOSS) ATTRIBUTABLE TO PAGP Impact to net income attributable to PAGP Net income (loss) attributable to PAGP Net Income (Loss) Attributable to Parent Consolidated Entities [Axis] Consolidated Entities [Axis] Emerging Growth Company Entity Emerging Growth Company Long-term operating lease right-of-use assets, net Operating Lease, Right-of-Use Asset Summary of open derivative positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Interest Rate Derivatives Interest Rate Contract [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Derivative position notional amount (in Terawatt hours) Derivative, Nonmonetary Notional Amount, Energy Measure Net Carrying Value Presented on the Balance Sheet Derivative liability Derivative Liability Consideration to be received for sale of assets Disposal Group, Including Discontinued Operation, Consideration Forward exchange contracts that exchange CAD For USD maturing in 2021 Foreign Exchange Forward Contracts That Exchange Canadian Dollars For US Dollars At Average Rate Disclosed Maturing in 2021 [Member] Foreign Exchange Forward Contracts That Exchange Canadian Dollars For US Dollars At Average Rate Disclosed Maturing in 2021 [Member] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Contracts with customers, change in contract liability balance Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Entity Filer Category Entity Filer Category Preferred unit distribution amount Dividends, Preferred Stock Other long-term assets, net Other Assets, Noncurrent Segments [Axis] Segments [Axis] 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] Net increase/(decrease) in cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Trade accounts payable and Other current liabilities Trade accounts payable and Other current liabilities [Member] Primary financial statement captions encompassing Trade accounts payable and Other current liabilities. Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Document Fiscal Year Focus Document Fiscal Year Focus Transaction [Domain] Transaction [Domain] Other Other Comprehensive Income, Other, Net of Tax Translation Adjustments Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Non-cash impairment losses upon classification to assets held for sale Impairment of Long-Lived Assets to be Disposed of Common equity repurchase program, remaining amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Other current assets Other Current Assets [Member] Total long-term debt Long-term Debt and Lease Obligation Proceeds from the issuance of PAA senior notes Proceeds from Issuance of Senior Long-term Debt Repurchase of common units by a subsidiary under Common Equity Repurchase Program (shares) Partners' Capital Account, Shares, Cancellation Of Shares Partners' Capital Account, Shares, Cancellation Of Shares Antidilutive securities excluded from computation of earnings per share (per share) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Amounts recognized as revenue (1) Contract with Customer, Liability, Revenue Recognized 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] Amount accrued to distributions payable Dividends Payable, Current 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 Business Combination and Asset Acquisition [Abstract] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Business Acquisition [Axis] Business Acquisition [Axis] Cash flow hedge Cash Flow Hedging [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] 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. Share Repurchase Program [Domain] Share Repurchase Program [Domain] Reconciliation from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] ASSETS Assets [Abstract] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Plains Oryx Permian Basin LLC Plains Oryx Permian Basin LLC [Member] Plains Oryx Permian Basin LLC 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. Derivatives and Risk Management Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Ownership interest Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest Unallocated Segment Reconciling Items [Member] Red River LLC Red River Pipeline Company LLC [Member] Red River Pipeline Company LLC [Member] Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Gain on/(impairment of) investments in unconsolidated entities, net (Gain on)/impairment of investments in unconsolidated entities, net Gain on/(impairment of) investments in unconsolidated entities, net Gain on (Impairment Of) Investments In Unconsolidated Entities, Net 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 and/or (iii) impairment of investment in unconsolidated entity. Entity Address, City or Town Entity Address, City or Town 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. Net Carrying Value Presented on the Balance Sheet, Total Derivative Assets (Liabilities), at Fair Value, Net Debt Instrument [Axis] Debt Instrument [Axis] Debt instrument fair value Debt Instrument, Fair Value Disclosure LONG-TERM LIABILITIES Liabilities, Noncurrent [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Common Units and Series A Preferred Units Common Units And Series A Preferred Units [Member] Common Units And Series A Preferred Units [Member] Distributions on earnings from unconsolidated entities Proceeds from Equity Method Investment, Distribution Common equity repurchase program, repurchased amount (dollars) Stock Repurchased and Retired During Period, Value 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. Inventory, Current [Table] Inventory, Current [Table] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Comprehensive income/(loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Average rate locked (percent) Derivative, Average Fixed Interest Rate Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] NGL and natural gas processing and fractionation NGL And Natural Gas Processing And Fractionation [Member] NGL And Natural Gas Processing And Fractionation [Member] PAA Plains All American Pipeline L P [Member] Represents the information pertaining to Plains All American Pipeline, L.P. ("PAA"). Entity Interactive Data Current Entity Interactive Data Current Number of interest rate derivatives Number of Interest Rate Derivatives Held Repurchase of common units by a subsidiary (Note 7) Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Repurchase of Shares by Subsidiary 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. Field operating costs Operating Expense [Member] Distribution Type [Axis] Distribution Type [Axis] Conversion of AAP Management Units (shares) Limited Partners Capital Shares Issued From Conversion Limited Partners Capital Shares Issued From Conversion Operating segments number Number of Operating Segments Other expense, net Other Nonoperating Income (Expense) [Member] BASIC NET INCOME/(LOSS) PER CLASS A SHARE (in dollars per share) Impact to basic net income per Class A share (in dollars per share) Earnings Per Share, Basic Revenues and Accounts Receivable Revenue from Contract with Customer [Text Block] Document Type Document Type Distributions paid to Class A shareholders (Note 7) Distribution Made to Limited Partner, Cash Distributions Paid Disaggregation of revenue Disaggregation of Revenue [Table Text Block] Consolidated Entity Excluding VIE Consolidated Entity, Excluding Consolidated VIE [Member] Civil Penalties Consent Decree, Civil Penalties [Member] Consent Decree, Civil Penalties Contract with Customer, Asset And Liability [Table] Contract With Customer, Asset And Liability [Table] Contract With Customer, Asset And Liability [Table] Entity Current Reporting Status Entity Current Reporting Status Other trade accounts receivables and other receivables Accounts and Other Receivables, Net, Current Commercial Paper Commercial Paper [Member] Other Other Noncash Income (Expense) Gross Position - Asset Derivative Asset, Fair Value, Gross Asset Long fuel gas position for fuel gas requirements Long Position On Fuel Gas Requirements Contracts [Member] Long Position On Fuel Gas Requirements Contracts Counterparty deficiencies Counterparty Deficiencies Amount associated with deficiencies by counterparties of their contractual minimum commitments. Trade accounts receivable and other receivables, net Trade accounts receivable and other receivables, net Receivables, Net, Current Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Estimated size of release (in bbl) Estimated Size of Release Represents the estimated size of the pipeline release. Recoveries from insurance carriers Loss Contingency, Receivable, Proceeds Rollforward of Level 3 Net Asset/(Liability) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Other Other Debt [Member] Other types of debt not specifically identified. Level 1 Fair Value, Inputs, Level 1 [Member] Goodwill impairment losses Goodwill impairment losses Goodwill, Impairment Loss Document Transition Report Document Transition Report Gains/(losses) from derivative activities and inventory valuation adjustments Gains (Losses) From Derivative Activities and 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. Total liabilities and partners’ capital Liabilities and Equity Currency Exchange Rate Risk Hedging: Foreign Currency Derivatives [Abstract] Transaction Type [Axis] Transaction Type [Axis] Scenario [Axis] Scenario [Axis] Crude oil transactions Crude Oil Transactions [Member] Crude Oil Transactions [Member] Noncontrolling interests Partners' Capital Attributable to Noncontrolling Interest Facilities 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. Class A shareholders (194,123,869 and 194,051,436 shares outstanding, respectively) Limited Partners' Capital Account LIABILITIES AND PARTNERS’ CAPITAL Liabilities and Equity [Abstract] GO Zone term loans GO Zone Term Loans [Member] GO Zone Term Loans [Member] Hedging Relationship [Domain] Hedging Relationship [Domain] Derivatives and Risk Management Activities Derivative [Line Items] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] CASH FLOWS FROM OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net Income/(Loss) Per Class A Share Earnings Per Share [Text Block] Net unrealized gain/(loss) recognized in AOCI for derivatives Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Crude Oil Sales Agreements Entered Into In Conjunction With Storage Arrangements And Future Inventory Exchanges Member Crude Oil Sales Agreements Entered Into In Conjunction With Storage Arrangements And Future Inventory Exchanges Member [Member] Crude Oil Sales Agreements Entered Into In Conjunction With Storage Arrangements And Future Inventory Exchanges Member Net repayments under PAA senior secured hedged inventory facility (Note 6) Net Proceeds from (Repayments of) Hedged Inventory Facility The net cash inflow (outflow) due to borrowings (repayments) on the hedged inventory facility. Other long-term debt, net Other Long-term Debt, Noncurrent Minimum Minimum [Member] Organization and Basis of Consolidation and Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Supply and Logistics 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. Deferred tax asset Partners Capital Deferred Tax Asset Represents the increase in partners capital from the deferred tax asset created during the period related to basis differences associated with transfers of ownership. Effect of translation adjustment Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Balance Sheet Location [Domain] Balance Sheet Location [Domain] Comprehensive (income)/loss attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Debt issuance costs Debt Issuance Costs, Net Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Proceeds from sales of assets Proceeds from Sale of Productive Assets 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. OTHER ASSETS Other Assets, Noncurrent [Abstract] Trading Symbol Trading Symbol Shares outstanding (shares) Balance, beginning of period (shares) Balance, end of period (shares) Limited Partners' Capital Account, Units Outstanding Deferred tax asset Deferred Income Tax Assets, Net CURRENT LIABILITIES Liabilities, Current [Abstract] General and administrative expenses Unallocated general and administrative expenses General and Administrative Expense Debt Debt Disclosure [Text Block] Line of Credit Line of Credit [Member] Senior notes Senior Notes [Member] Level 3 Fair Value, Inputs, Level 3 [Member] 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. 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. Accounting Policies [Abstract] Accounting Policies [Abstract] Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments [Abstract] Derivative Instrument [Axis] Derivative Instrument [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Outstanding letters of credit Letters of credit Letters of Credit Outstanding, Amount 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. (Gain)/loss on foreign currency revaluation Foreign Currency Transaction Gain (Loss), before Tax Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] COMMITMENTS AND CONTINGENCIES (NOTE 10) Commitments and Contingencies Net loss deferred in AOCI Accumulated Other Comprehensive Income (Loss), Net of Tax Beginning Balance Ending Balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Inventory valuation adjustments Inventory Write-down Partner Capital Components [Domain] Partner Capital Components [Domain] Statement of Partners' Capital [Abstract] Statement of Partners' Capital [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. Total borrowings Proceeds from Issuance of Debt 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. Disposal Group Classification [Axis] Disposal Group Classification [Axis] Ownership [Axis] Ownership [Axis] Document Period End Date Document Period End Date 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. Trade accounts receivable and other receivables, net from related parties Due from Related Parties, Current Dilutive LTIP awards (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Total costs and expenses Costs and Expenses Entity Registrant Name Entity Registrant Name Short condensate 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. Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Unitholder Derivative Lawsuits Unitholder Derivative Lawsuits [Member] Represents information related to unitholder derivative lawsuits filed against the company. Distribution Type [Domain] Distribution Type [Domain] 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. Amounts probable of recovery under insurance and from third parties under indemnification agreements Recorded Third-Party Environmental Recoveries Receivable 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 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. Revenues from related parties Revenue from Related Parties Cash paid in connection with acquisitions, net of cash acquired Payments to Acquire Businesses and Interest in Affiliates Revenues from contracts with customers Revenues from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax 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 misdemeanor charges found 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 Adjustments: Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract] Other items in revenues Revenue Not from Contract with Customer Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Net broker receivable/(payable) Effect of Collateral Netting Derivative Liability, Collateral, Right to Reclaim Cash, Offset 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 Operating Segments Segment Reporting Disclosure [Text Block] OPERATING INCOME/(LOSS) Operating Income (Loss) 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 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. Derivative Liability Positions Offsetting Derivative Liabilities [Abstract] 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. Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Hedging Designation [Axis] Hedging Designation [Axis] Other Other Long Term Debt [Member] Other types of long-term debt not specifically identified. Change in Accounting Estimate, Type [Domain] Change in Accounting Estimate, Type [Domain] Field operating costs Operating Costs and Expenses Senior Secured Hedged Inventory Facility Senior Secured Hedged Inventory Facility [Member] Represents activity related to Senior secured hedged inventory credit facility. Inventory [Axis] Inventory [Axis] Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Increase in depreciation expense Depreciation Number of felony discharges found guilty Indictment, Number of Felony Discharges, Guilty Verdict Indictment, Number of Felony Discharges, Guilty Verdict Forward exchange contracts that exchange USD for CAD maturing in 2021 Foreign Exchange Forward Contracts That Exchange U S Dollars For Canadian Dollars At Average Rate Disclosed Maturing In 2021 [Member] Foreign Exchange Forward Contracts That Exchange U S Dollars For Canadian Dollars At Average Rate Disclosed Maturing In 2021 [Member] Total repayments Repayments of Debt Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Total tariff activities Tariff Activities [Member] Tariff Activities [Member] AAP Management Units AAP Management Units [Member] AAP Management Units Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Notional amount of derivatives Derivative, Notional Amount Other income/(expense), net Other income/(expense), net Other Nonoperating Income (Expense) Series A Preferred Units Series A 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. Repurchase and cancellation of common units by a subsidiary under the Common Equity Repurchase Program (units) Stock Repurchased and Retired During Period, Shares Other investing activities Payments for (Proceeds from) Other Investing Activities Additions to property, equipment and other Payments to Acquire Property, Plant, and Equipment Other current liabilities Other Liabilities, Current Total net derivative asset/(liability) Derivative, Fair Value, Net Distributions (Note 7) Total distributions paid Partners' Capital Account, Distributions Partners' Capital and Distributions Partners' Capital Notes Disclosure [Text Block] Net 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. Maximum Maximum [Member] Class Action Lawsuits Class Action Lawsuits [Member] Represents information related to class action lawsuits filed against the company. Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Legal Entity [Axis] Legal Entity [Axis] Additional Interests in Straddle Plants Additional Interests in Straddle Plants [Member] Additional interests in two straddle plants acquired through an asset exchange agreement. Consolidation Items [Axis] Consolidation Items [Axis] Settlement of terminated interest rate hedging instruments Net Cash (Paid) Received for Terminated Hedging Instruments The net cash (paid) received for terminated hedging instruments. 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. General payment terms Revenue, Performance Obligation, Description of Payment Terms Partner Capital Components [Axis] Partner Capital Components [Axis] Derivatives in Hedging Relationships Designated as Hedging Instrument [Member] 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. Storage, terminalling and throughput agreement revenues Long-Term Storage, Terminalling And Throughput Agreements Revenues [Member] Long-Term Storage, Terminalling And Throughput Agreements Revenues [Member] Repayments of PAA senior notes Repayments of Senior Debt Interest expense, capitalized interest Interest Costs Capitalized Changes in assets and liabilities, net of acquisitions Increase (Decrease) in Operating Capital Property and equipment, useful life Property, Plant and Equipment, Useful Life Changes in Accumulated Other Comprehensive Income/(Loss) AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Interest Rate Risk Hedging Interest Rate Derivatives [Abstract] Public Public Unit Holders [Member] Public Unit Holders [Member] Long-term operating lease liabilities Operating Lease, Liability, Noncurrent Measurement Frequency [Domain] Measurement Frequency [Domain] Change in unrealized losses included in earnings relating to Level 3 derivatives still held at the end of the period Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss) Debt instrument face value Debt Instrument, Face Amount Current income tax expense Current Income Tax Expense (Benefit) Interest expense (net of capitalized interest of $5, $5, $10 and $11, respectively) Interest expense, net Interest Expense Weighted average interest rate, short-term Short-term Debt, Weighted Average Interest Rate, at Point in Time Interest rate fair value hedge liability at fair value Interest Rate Fair Value Hedge Liability at Fair Value Change in Useful Life Service Life [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Other Other Inventory [Member] Category of inventory not separately disclosed. City Area Code City Area Code Crude oil Crude Oil [Member] Supply and Logistics segment revenues Sales And Related Revenues [Member] Revenue from the sale of crude oil, NGL and natural gas during the period. Operating Segments Operating Segments [Member] Linefill and base gas (Price/Unit of measure) Inventory, Weighted Average Price Per Unit, Linefill and Base Gas1 Inventory, Weighted Average Price Per Unit, Linefill and Base Gas1 Litigation Case [Domain] Litigation Case [Domain] Derivative assets and liabilities Derivatives, Fair Value [Line Items] Other AOCI, Other, Including Portion Attributable to Noncontrolling Interest [Member] AOCI, Other, Including Portion Attributable to Noncontrolling Interest [Member] Asset Exchange Transaction Asset Exchange Transaction [Member] Transaction whereby additional interests in two straddle plants were acquired in exchange for cash and a pipeline and related storage and truck facilities. Business Acquisition [Line Items] Business Acquisition [Line Items] Impact of derivatives recognized in earnings Derivative Instruments, Gain (Loss) [Table Text Block] Segment Reporting, Reconciling Item from Segments to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Common Units Common Units [Member] Common units representing limited partner interests in the entity. Reconciliation of cash and cash equivalents and restricted cash Restrictions on Cash and Cash Equivalents [Table Text Block] Income Statement [Abstract] Income Statement [Abstract] Investments in unconsolidated entities Equity Method Investments Amendment Flag Amendment Flag Pine Prairie and Southern Pines Natural Gas Storage Facilities Pine Prairie and Southern Pines Natural Gas Storage Facilities [Member] Pine Prairie and Southern Pines Natural Gas Storage Facilities Number of straddle plants, additional interests acquired Number of Straddle Plants, Additional Interests Acquired Number of Straddle Plants, Additional Interests Acquired Inventory by category Inventory Disclosure [Abstract] Partner Type [Axis] Partner Type [Axis] 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. Joint Venture Transaction Joint Venture Transaction [Member] Joint Venture Transaction Other long-term assets, net Other long-term assets, net Other Noncurrent Assets [Member] Term loan Term Loan [Member] Term Loan [Member] Substantially all trade accounts receivable, net, maximum age of balances past their invoice date Trade Accounts Receivable Net Disclosure of Maximum Age of Balances Past Invoice Date The maximum number of days past their invoice date for substantially all of the trade accounts receivable. Preferred unit distribution amount (in dollars per unit) Preferred Stock, Dividends, Per Share, Cash Paid Income tax (expense)/benefit Income Tax Expense (Benefit) Term of derivative contract Derivative, Term of Contract Inventory, Volumes (in barrels) Inventory, Volumes Current The volume of current inventory as of the balance sheet date. Equity Components [Axis] Equity Components [Axis] AAP AAP Plains AAP L P [Member] Represents information pertaining to Plains, AAP L.P (AAP). Total current assets Assets, Current Distributions to PAGP SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Inventory Inventory, Net Line 901 Incident Line 901 Incident [Member] Represents information pertaining to the crude oil release from the Las Flores to Gaviota Pipeline in Santa Barbara County, California. Reclassification adjustments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Segment financial data Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of activity for Class A shares, Class B shares and Class C shares Schedule of Stockholders Equity [Table Text Block] Entity File Number Entity File Number Revenues: Segment Reporting Information, Revenue for Reportable Segment [Abstract] Recurring Fair Value Measurements Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] 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. Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Estimated undiscounted reserve for environmental liabilities, short-term Accrued Environmental Loss Contingencies, Current Schedule of related party transactions Schedule of Related Party Transactions [Table Text Block] Product and Service [Axis] Product and Service [Axis] Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] CASH FLOWS FROM FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Impact of derivative activities recognized in earnings Derivative Instruments, Gain (Loss) [Line Items] Small Business Entity Entity Small Business Ownership interest (in 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. 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 Commodity Price Risk Hedging: Price Risk Derivatives [Abstract] Contract with Customer Assets And Liabilities [Line Items] Contract With Customer Assets And Liabilities [Line Items] Contract With Customer Assets And Liabilities Equity Component [Domain] Equity Component [Domain] Currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Disposal Group Name [Domain] Disposal Group Name [Domain] Increase (Decrease) in Partners' Capital Activity for Class A shares, Class B shares and Class C shares Increase (Decrease) in Partners' Capital [Roll Forward] Change in fair value of Preferred Distribution Rate Reset Option (Note 8) Gain/(loss) recognized Embedded Derivative, Gain (Loss) on Embedded Derivative, Net Statement [Line Items] Statement [Line Items] Litigation Case [Axis] Litigation Case [Axis] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Credit facilities 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. Unrealized gain (loss) on hedges Net unrealized gain/(loss) recognized in AOCI Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Purchases and related costs from related parties Related Party Transaction, Purchases from Related Party Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Debt Disclosure [Abstract] Debt Disclosure [Abstract] 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. Entity Address, State or Province Entity Address, State or Province INCOME/(LOSS) BEFORE TAX Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Level 2 Fair Value, Inputs, Level 2 [Member] Long-term inventory, Volumes (in barrels) Inventory, Volumes, Noncurrent The volume of noncurrent inventory as of the balance sheet date. Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Total partners’ capital Beginning balance Ending balance Deferred losses on hedges remaining in other comprehensive income Partners' Capital, Including Portion Attributable to Noncontrolling Interest Total gain/(loss) on derivatives recognized in net income Derivative, Gain (Loss) on Derivative, Net Segment Reporting [Abstract] Segment Reporting [Abstract] Entity [Domain] Entity [Domain] Long-term inventory (Price/Unit of measure) Inventory, Weighted Average Price Per Unit, Noncurrent1 Inventory, Weighted Average Price Per Unit, Noncurrent1 Commodity Derivatives Commodity Contract [Member] Senior notes, net Senior Notes, Noncurrent Calculation of basic and diluted net income/(loss) per Class A share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Entity Shell Company Entity Shell Company Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Local Phone Number Local Phone Number Forecast Forecast [Member] Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Total assets Assets NGL pipelines Tariff Activities, NGL Pipelines [Member] Tariff Activities, NGL Pipelines [Member] Repurchase of common units by a subsidiary (Note 7) Payments to Noncontrolling Interests 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. Short-term debt: Short-term Debt [Abstract] Interest, net of amounts capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Partners' Capital and Distributions [Table] Partners' Capital and Distributions [Table] Disclosure reflecting information pertaining to Partners' Capital and related distributions. Other Partners' Capital, Other Product and Service [Domain] Product and Service [Domain] Noncontrolling Interests Noncontrolling Interest [Member] Stated percentage Debt Instrument, Interest Rate, Stated Percentage Derivative Contract [Domain] Derivative Contract [Domain] Contributions from noncontrolling interests Partners' Capital Account, Contributions Net (income)/loss attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Contract with customer, counterparty deficiencies Contract with Customer, Counterparty Deficiencies [Table Text Block] Contract with Customer, Counterparty Deficiencies Total long-term liabilities Liabilities, Noncurrent Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Remaining performance obligations, expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Minimum Volume Commitments [Line Items] Contract With Customer, Asset And Liability [Line Items] [Line Items] for Contract With Customer, Asset And Liability [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Short-term debt Short-term Debt Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Schedule of debt Schedule of Debt [Table Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Entity Tax Identification Number Entity Tax Identification Number Change in Accounting Estimate by Type [Axis] Change in Accounting Estimate by Type [Axis] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] BASIC WEIGHTED AVERAGE CLASS A SHARES OUTSTANDING (in shares) Basic weighted average Class A shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic DILUTED NET INCOME/(LOSS) PER CLASS A SHARE (in dollars per share) Impact to diluted net income per Class A share (in dollars per share) Earnings Per Share, Diluted Segments [Domain] Segments [Domain] Trade accounts payable to related parties Due to Related Parties, Current PARTNERS’ CAPITAL Partners' Capital, Including Portion Attributable to Noncontrolling Interest [Abstract] Inventory, Linefill and Base Gas and Long-term Inventory Inventory, Linefill and Base Gas and Long-term Inventory Penalties or compensation paid Loss Contingency, Damages Paid, Value Hedging Relationship [Axis] Hedging Relationship [Axis] Weighted average interest rate, long-term Long-term Debt, Weighted Average Interest Rate, at Point in Time Schedule of distributions Distributions Made to Limited Partner, by Distribution [Table Text Block] Income taxes, net of amounts refunded Income Taxes Paid, Net Acquisitions, Divestitures and Other Transactions Mergers, Acquisitions and Dispositions Disclosures [Text Block] Consent Decree, Compensation for Injuries to, Destruction of, Loss of Use of, Natural Resources Consent Decree, Compensation for Injuries to, Destruction of, Loss of Use of, Natural Resources [Member] Consent Decree, Compensation for Injuries to, Destruction of, Loss of Use of, Natural Resources Partners' Capital Notes [Abstract] Partners' Capital Notes [Abstract] Distributions paid to noncontrolling interests (Note 7) Payments of Ordinary Dividends, Noncontrolling Interest Comprehensive income/(loss) attributable to PAGP Comprehensive Income (Loss), Net of Tax, Attributable to Parent Counterparty deficiencies billed and collected Beginning balance Ending balance Contract with Customer, Liability Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Change in Contract with Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Other long-term liabilities and deferred credits Other long-term liabilities and deferred credits Other Noncurrent Liabilities [Member] Equity earnings in unconsolidated entities Equity earnings in unconsolidated entities Income (Loss) from Equity Method Investments Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization Counterparty deficiencies unbilled 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. 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] Pipeline revenues supported by minimum volume commitments and 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 Fines or penalties assessed Loss Contingency Penalty or Fine Assessed Represents penalty or fine assessed on the entity in connection with an environmental matter. Preferred Distribution Rate Reset Option Embedded Derivative Financial Instruments [Member] Derivative [Table] Derivative [Table] (Gains)/losses on asset sales and asset impairments, net (Gains)/losses on asset sales and asset impairments, net Gains/(losses) on asset sales and asset impairments, net Gain on divestiture of assets Gain (Loss) on Sale of Assets and Asset Impairment Charges Rail load / unload Rail Load And Unload [Member] Rail Load And Unload [Member] Purchases and related costs Cost of Goods and Services Sold REVENUES Revenues [Abstract] Estimated undiscounted reserve for environmental liabilities Accrual for Environmental Loss Contingencies, Gross Common Equity Repurchase Program Common Equity Repurchase Program [Member] Common Equity Repurchase Program Remaining performance obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Net gain 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. Inventory [Domain] Inventory [Domain] Consolidated Entities [Domain] Consolidated Entities [Domain] CASH FLOWS FROM INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Pipeline and related facilities and Storage, terminal and rail facilities Pipeline And Related Facilities And Storage, Terminal And Rail Facilities [Member] Pipeline And Related Facilities And Storage, Terminal And Rail Facilities Income Statement Location [Domain] Income Statement Location [Domain] Derivative position notional amount (in barrels, MMbls or Bcf) Derivative, Nonmonetary Notional Amount, Volume Disposal Group, Held-for-sale, Not Discontinued Operations Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Legal, Environmental or Regulatory Matters Loss Contingencies [Line Items] Property and equipment, net Property, Plant and Equipment, Net 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. Operating Segments Excluding Intersegment Elimination Operating Segments Excluding Intersegment Elimination [Member] Operating Segments Excluding Intersegment Elimination Total AOCI Including Portion Attributable to Noncontrolling Interest [Member] Other long-term liabilities and deferred credits Other Liabilities, Noncurrent Net repayments under PAA commercial paper program (Note 6) Proceeds from (Repayments of) Commercial Paper Gross Position - Liability Derivative Asset, Fair Value, Gross Liability (Gains)/losses on asset sales and asset impairments, net (Gains)/Losses On Asset Sales And Asset Impairments, Net [Member] (Gains)/Losses On Asset Sales And Asset Impairments, Net Debt Debt Instrument [Line Items] Earnings Per Share [Abstract] Earnings Per Share [Abstract] NGL Natural Gas Liquids [Member] Net Carrying Value Presented on the Balance Sheet Derivative asset Derivative Asset 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. PROPERTY AND EQUIPMENT Property, Plant and Equipment, Gross Document Quarterly Report Document Quarterly Report Total revenues Revenues Revenues Partners' Capital and Distributions Partners Capital and Distribution [Line Items] Partners Capital and Distribution [Line Items] No definition available. Derivative Instruments Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] 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. Gross Position - Asset Derivative Liability, Fair Value, Gross Asset Other current liabilities Other Current Liabilities [Member] Foreign Currency Derivatives Foreign Exchange Contract [Member] Total Inventory, Current and Noncurrent This element represents the aggregate of current and non-current inventory, including linefill and base gas. Entity Common Stock, Shares Outstanding (shares) Entity Common Stock, Shares Outstanding COSTS AND EXPENSES Costs and Expenses [Abstract] 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. Total debt Debt and Lease Obligation Basic and Diluted Net Income/(Loss) per Class A Share Earnings Per Share, Basic and Diluted [Abstract] Noncontrolling interests in subsidiaries (percent) Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Document Fiscal Period Focus Document Fiscal Period Focus Oryx Midstream Holdings LLC Oryx Midstream Holdings LLC [Member] Oryx Midstream Holdings LLC Aggregate total estimated costs Loss Contingency, Estimate of Possible Loss Crude oil pipelines Tariff Activities, Crude Oil Pipelines [Member] Tariff Activities, Crude Oil Pipelines [Member] NET INCOME/(LOSS) Net income/(loss) Net income/(loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Short-term debt Total short-term debt Debt, Current Restricted cash Restricted Cash, Current Counterparty Name [Axis] Counterparty Name [Axis] Trade accounts receivable arising from revenues from contracts with customers Contract with Customer, Asset, after Allowance for Credit Loss, Current Cash and cash equivalents and restricted cash, beginning of period Cash and cash equivalents and restricted cash, end of period Total cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Schedule of terms of outstanding interest rate derivatives Schedule of Derivative Instruments [Table Text Block] Exchange traded Exchange Traded [Member] 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. Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] CURRENT ASSETS Assets, Current [Abstract] Other financing activities Proceeds from (Payments for) Other Financing Activities 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. Entity Central Index Key Entity Central Index Key Number of misdemeanor charges found guilty Indictment, Number of Misdemeanor Charges, Guilty Verdict Indictment, Number of Misdemeanor Charges, Guilty Verdict Security Exchange Name Security Exchange Name 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. Disposal Group Classification [Domain] Disposal Group Classification [Domain] Long-term inventory Inventory, Noncurrent Significant transaction-related expenses Significant transaction-related expenses Significant expenses associated with joint venture transactions and acquisitions 8 forward starting interest rate swaps (30-year), 1.38% Eight Forward Starting Thirty Year Interest Rate Swaps 1.38 Percent [Member] Eight Forward Starting Thirty Year Interest Rate Swaps 1.38 Percent DILUTED WEIGHTED AVERAGE CLASS A SHARES OUTSTANDING (in shares) Diluted weighted average Class A shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Other comprehensive income/(loss) Total period activity Other Comprehensive Income (Loss), Net of Tax Recurring Fair Value Measures Fair Value, Recurring [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Average exchange rate (cad per usd) Derivative, Average Forward Exchange Rate 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. AOCI cash flow hedge Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] OTHER INCOME/(EXPENSE) Nonoperating Income (Expense) [Abstract] Inter Pipeline Ltd Inter Pipeline Ltd [Member] Inter Pipeline Ltd 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. Derivatives Not Designated as a Hedge Not Designated as Hedging Instrument [Member] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Reconciliation of segment adjusted EBITDA to Net income/(loss) attributable to PAGP Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] NGL and other transactions NGL And Other Transactions [Member] NGL And Other Transactions [Member] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment 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. 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. Offsetting Assets, Liabilities [Line Items] Derivative and financial assets and liabilities subject to collateral netting Offsetting Assets, Liabilities [Line Items] Natural gas Natural Gas [Member] Total current liabilities Liabilities, Current Cash consideration, including working capital and other adjustments Payments to Acquire Businesses, Gross 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. Intersegment Intersegment Eliminations [Member] Limited Partners Limited Partner [Member] Long natural gas position for natural gas purchases for processing 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. Gain/(loss) recognized in earnings Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments Trade accounts payable Accounts Payable, Trade, Current Loss Contingencies [Table] Loss Contingencies [Table] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Trade accounts receivable and other receivables, net Trade Accounts Receivable And Other Receivables Net [Member] Primary financial statement caption encompassing trade accounts receivable and other receivables, net. Ownership [Domain] Ownership [Domain] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Inventory (Price/Unit of measure) Inventory, Weighted Average Price Per Unit, Current1 Inventory, Weighted Average Price Per Unit, Current1 Unamortized discounts and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Assets held for sale, current Disposal Group, Including Discontinued Operation, Assets, Current Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Title of 12(b) Security Title of 12(b) Security Cash Distribution Cash Distribution [Member] Shares outstanding Limited Partners' Capital Account [Line Items] Other current assets Other Assets, Current Statement [Table] Statement [Table] Recent Accounting Pronouncements and Accounting Standards Updates Adopted During the Period New Accounting Pronouncements, Policy [Policy Text Block] Segment Adjusted EBITDA 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 and losses 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. Long-term debt: Long-term Debt, Unclassified [Abstract] Number of cases filed during the period Loss Contingency, New Claims Filed, Number Statistical Measurement [Axis] Statistical Measurement [Axis] Gross Position - Liability Derivative Liability, Fair Value, Gross Liability Cover page. Cover [Abstract] Distributions to Class A shareholders Distributions to common unitholders Limited Partners' Capital Account, Distribution Amount Equity-indexed compensation expense Equity Indexed Compensation Expense Awards That Will Be Settled In Units Expense associated with equity-indexed compensation awards that will be settled in units. Derivative Asset Positions Offsetting Derivative Assets [Abstract] Effect of Collateral Netting Offsetting [Abstract] 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. Distribution per Class A share, paid (usd per share) Distributions per common unit, paid (usd per unit) Distribution Made to Limited Partner, Distributions Paid, Per Unit Scenario [Domain] Scenario [Domain] Reconciliation of net income/(loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Trucking Trucking [Member] Trucking [Member] Variation margin posted/(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. 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] Related Party Transactions Related Party Transactions Disclosure [Text Block] 3.65% senior notes due June 2022 Senior Notes Due In June 2022 At 3.65 Percent [Member] Senior Notes Due In June 2022 At 3.65 Percent Inventory [Line Items] Inventory [Line Items] AAP Units AAP Units [Member] AAP Units Deferred income tax (expense)/benefit Deferred income tax expense/(benefit) Deferred Income Tax Expense (Benefit) Schedule of net broker receivable/(payable) Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block]