Document and Entity Information Statement [Table] Statement [Line Items] Statement Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus CONSOLIDATED BALANCE SHEETS Schedule of Limited Partners' Capital Account by Class [Table] Limited Partners' Capital Account by Class [Axis] Limited Partners Capital Account Class [Domain] Limited Partners' Capital Account, Class [Domain] Represents the classification of common 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. Common Shares Class A [Member] Class A Shares Represents the classification of common 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. Common Shares Class B [Member] Class B Shares Limited Partners' Capital Account [Line Items] Shares outstanding Statement Assets [Abstract] ASSETS Assets, Current [Abstract] CURRENT ASSETS Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period Cash and cash equivalents Receivables, Net, Current Trade accounts receivable and other receivables, net Inventory, Net Inventory Other Assets, Current Other current assets Assets, Current Total current assets Property, Plant and Equipment, Gross PROPERTY AND EQUIPMENT Property and equipment, gross Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depreciation Property, Plant and Equipment, Net Property and equipment, net Other Assets, Noncurrent [Abstract] OTHER ASSETS Other Assets, Net Goodwill. Balance at end of period Balance at beginning of period Goodwill Equity Method Investments Investments in unconsolidated entities Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred tax asset Crude oil, refined products, and NGL linefill in pipelines and base gas in natural gas storage facilities that are owned by the entity. The linefill and base gas are intended for long-term use. Linefill and Base Gas Linefill and base gas Inventory, Noncurrent Long-term inventory Other Assets, Noncurrent Other, net Other assets, net Assets Total assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND PARTNERS' CAPITAL Liabilities, Current [Abstract] CURRENT LIABILITIES Accounts Payable and Accrued Liabilities, Current Accounts payable and accrued liabilities Debt, Current Short-term debt Total short-term debt Other Liabilities, Current Other current liabilities Liabilities, Current Total current liabilities Liabilities, Noncurrent [Abstract] LONG-TERM LIABILITIES Senior Notes, Noncurrent PAA senior notes, net of unamortized discounts Senior notes, net of unamortized discount of $18 and $15, respectively Other Long-term Debt, Noncurrent Other long-term debt Liabilities, Other than Long-term Debt, Noncurrent Other long-term liabilities and deferred credits Liabilities, Noncurrent Total long-term liabilities Commitments and Contingencies. COMMITMENTS AND CONTINGENCIES (NOTE 17) Partners' Capital, Including Portion Attributable to Noncontrolling Interest [Abstract] PARTNERS' CAPITAL Partners' Capital Partners' Capital Partners' Capital Attributable to Noncontrolling Interest Noncontrolling interests Partners' Capital, Including Portion Attributable to Noncontrolling Interest Balance, end of period Balance, beginning of period Total partners' capital Liabilities and Equity Total liabilities and partners' capital Debt Instrument, Unamortized Discount Unamortized discounts Senior notes, unamortized discount Limited Partners' Capital Account, Units Outstanding Balance, end of period (in shares) Balance, beginning of period (in shares) Shares outstanding CONSOLIDATED STATEMENTS OF OPERATIONS Revenues [Abstract] REVENUES Revenue from the sale of crude oil, refined products, NGL and natural gas storage during the period, primarily from supply and logistics activities. Sales and Related Revenues Supply and Logistics segment revenues Revenue from the transportation of crude oil, NGL and refined products, primarily on pipelines and trucks, and related activities during the period. Pipeline Tariff Activities Trucking and Related Revenues Transportation segment revenues Revenue from the storage, terminalling and processing of crude oil, refined products, NGL and natural gas during the period. Storage Terminalling Processing and Related Revenues Facilities segment revenues Revenues Revenues Total revenues Costs and Expenses [Abstract] COSTS AND EXPENSES Costs related to the purchase of crude oil, refined products, NGL and natural gas storage during the period, primarily from gathering and marketing activities. Purchases and Related Costs Purchases and related costs Operating Costs and Expenses Field operating costs General and Administrative Expense General and administrative expenses Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Depreciation and amortization Costs and Expenses Total costs and expenses Operating Income (Loss) OPERATING INCOME Operating income Nonoperating Income (Expense) [Abstract] OTHER INCOME/(EXPENSE) Income (Loss) from Equity Method Investments Equity earnings in unconsolidated entities Equity earnings in unconsolidated entities Interest Expense Interest expense, net Interest expense (net of capitalized interest of $48, $38 and $36, respectively) Other Nonoperating Income (Expense) Other income/(expense), net Other income/(expense), net Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income before tax INCOME BEFORE TAX Current Income Tax Expense (Benefit) Current income tax expense Current income tax expense Deferred Income Tax Expense (Benefit) Deferred income tax expense Deferred income tax expense Total deferred tax (benefit)/expense Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income NET INCOME Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Parent NET INCOME ATTRIBUTABLE TO PAGP Net income attributable to PAGP Earnings Per Share, Basic BASIC NET INCOME PER CLASS A SHARE (in dollars per share) Basic net income per Class A Shares (in dollars per share) Earnings Per Share, Diluted DILUTED NET INCOME PER CLASS A SHARE (in dollars per share) Diluted net income per Class A share (in dollars per share) Weighted Average Number of Shares Outstanding, Basic BASIC WEIGHTED AVERAGE CLASS A SHARES OUTSTANDING (in shares) Basic weighted average Class A shares outstanding Weighted Average Number of Shares Outstanding, Diluted DILUTED WEIGHTED AVERAGE CLASS A SHARES OUTSTANDING (in shares) Diluted weighted average Class A shares outstanding Interest Costs Capitalized Capitalized interest Interest expense, capitalized interest CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Other Comprehensive Income (Loss), Net of Tax Total period activity Other comprehensive income/(loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to PAGP CONSOLIDATED STATEMENTS OF CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME / (LOSS) Partner Capital Components [Axis] Partner Capital Components [Domain] Partner Capital Components [Domain] Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] Derivative Instruments Accumulated Translation Adjustment [Member] Translation Adjustments Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] Increase (Decrease) in Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Loss), Net of Tax Balance at end of period Balance at beginning of period Net deferred gains/(losses) from interest rate risk hedging included in AOCI Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Reclassification adjustments Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Deferred gain (loss) on cash flow hedges, net of tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Currency translation adjustments CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Reconciliation of net income to net cash provided by operating activities: Share-based Compensation Equity-indexed compensation expense Inventory Write-down Inventory valuation adjustments Charge related to the write-down of inventory The difference between the sale price and book value of linefill and base gas that was sold during the reporting period. Gain (Loss) on Sale of Linefill and Base Gas Gain on sales of linefill and base gas Gain on sales of linefill and base gas Foreign Currency Transaction Gain (Loss), before Tax (Gain)/loss on foreign currency revaluation Gain (loss) on revaluation of foreign currency transactions and monetary assets and liabilities The net cash received (paid) for terminated hedging instruments, excluding any gain or loss recognized in earnings attributable to the ineffective portion of the derivative. Net Cash Received (Paid) for Terminated Hedging Instruments Settlement of terminated interest rate hedging instruments Proceeds from Equity Method Investment, Dividends or Distributions Distributions from unconsolidated entities Other Noncash Income (Expense) Other Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities, net of acquisitions: Increase (Decrease) in Accounts and Other Receivables Trade accounts receivable and other Increase (Decrease) in Inventories Inventory Increase (Decrease) in Accounts Payable and Accrued Liabilities Accounts payable and other current liabilities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES Payments to Acquire Businesses, Net of Cash Acquired Cash paid in connection with acquisitions, net of cash acquired (Note 3) Payments to Acquire Property, Plant, and Equipment Additions to property, equipment and other The cash inflow associated with the sale of linefill and base gas. Cash Received Related to Sales of Linefill and Base Gas Cash received for sales of linefill and base gas The cash outflow associated with the purchase of linefill and base gas. Cash Paid Related to Purchases of Linefill and Base Gas Cash paid for purchases of linefill and base gas Payments to Acquire Equity Method Investments Investment in unconsolidated entities (Note 8) Payments to acquire or subsequent contributions to unconsolidated entities Proceeds from Sale of Productive Assets Proceeds from sales of assets Proceeds from sale of various property and equipment Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital Cash received upon formation of equity-method investment Payments for (Proceeds from) Other Investing Activities Other investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] CASH FLOWS FROM FINANCING ACTIVITIES The net cash inflow (outflow) due to borrowings (repayments) on the short-term letter of credit and hedged inventory facility. Net Proceeds from (Repayments of) Short Term Letter of Credit and Hedged Inventory Facility Net borrowings/(repayments) under PAA senior secured hedged inventory facility (Note 10) The net cash inflow (outflow) due to borrowings (repayments) on the senior unsecured revolving credit facility. Net Proceeds from (Repayments of) Senior Unsecured Revolving Credit Facilities Net borrowings/(repayments) under PAA senior unsecured revolving credit facility (Note 10) The net cash inflow (outflow) due to borrowings (repayments) under a credit agreement of a consolidated subsidiary of the entity. Net Proceeds from (Repayments of) Subsidiary Credit Agreement Net borrowings/(repayments) under PNG credit agreement Proceeds from (Repayments of) Commercial Paper Net borrowings/(repayments) under PAA commercial paper program (Note 10) Repayment of commercial paper notes Proceeds from (Repayments of) Secured Debt Net borrowings/(repayments) under AAP senior secured revolving credit facility (Note 10) Proceeds from Issuance of Debt Increase in term loan Total borrowings Proceeds from AAP term loan (Note 11) Proceeds from Issuance of Senior Long-term Debt Proceeds from the issuance of PAA senior notes (Note 10) Repayments of Senior Debt Repayments of PAA senior notes (Note 10) Repayments of senior notes Proceeds from Noncontrolling Interests Net proceeds from the issuance of common units by subsidiaries (Note 11) Proceeds from Contributions from Affiliates Contributions from noncontrolling interests related to issuances of common units by subsidiaries Proceeds from Issuance Initial Public Offering Net proceeds from shares sold, after deducting underwriting discounts and commissions and direct offering expenses Proceeds received from initial public offering (Note 11) Represents the cash outflow due to distribution of proceeds received from initial public offering. Distribution of Proceeds from Issuance Initial Public Offering Distribution of proceeds received from initial public offering (Note 11) Distribution Made to Limited Partner, Cash Distributions Paid Distributions paid to Class A shareholders (Note 11) Distributions paid to Class A shareholders Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid Distributions paid to members (Note 11) Payments of Ordinary Dividends, Noncontrolling Interest Distributions paid to noncontrolling interests (Note 11) Proceeds from (Payments for) Other Financing Activities Other financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash provided by/(used in) financing activities Effect of Exchange Rate on Cash and Cash Equivalents, Continuing Operations Effect of translation adjustment on cash Cash and Cash Equivalents, Period Increase (Decrease) Net increase/(decrease) in cash and cash equivalents Supplemental Cash Flow Information [Abstract] Cash paid for: Interest Paid, Net Interest, net of amounts capitalized Income Taxes Paid, Net Income taxes, net of amounts refunded CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL / MEMBERS' EQUITY Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Member Units [Member] Members' Equity (Excluding Noncontrolling Interests) Partner Type [Axis] Partner Type Of Partners Capital Account Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Limited Partner [Member] Partners' Capital (Excluding Noncontrolling Interests) Noncontrolling Interest [Member] Noncontrolling Interests Increase (Decrease) in Partners' Capital [Roll Forward] Increase (Decrease) in Partners' Capital Partners' Capital Account, Distributions Distributions Total distributions paid during the period Represents the increase (decrease) in partners' capital accounts as a result of the transfer of ownership interest from noncontrolling interests to the parent in connection with the reorganization prior to initial public offering. Partners Capital Account Transfer of Ownership Interest Transfer of ownership interest in connection with reorganization prior to initial public offering (Note 11) Stock Issued During Period, Value, New Issues Issuance of Class A shares to the public, net of offering and other costs (Note 11) Decrease in partners' capital from the distribution of the net proceeds received from the initial public offering of the entity. Distribution of Proceeds from Initial Public Offering Distribution of net proceeds of initial public offering (Note 11) Represents the increase in partners capital from the deferred tax asset created during the period related to basis differences associated with transfers of ownership. Partners Capital Deferred Tax Asset Deferred tax asset (Note 13) Represents the increase (decrease) in partners' capital accounts as a result of the change in ownership interest from noncontrolling interests to the parent in connection with Exchange Right exercises. Partners Capital Account Change in Ownership Interest Change in ownership interest in connection with Exchange Right exercises (Note 11) Noncontrolling Interest, Increase from Subsidiary Equity Issuance Issuance of common units by subsidiaries Represents the impact to each class of partners' capital associated with the value of units issued during the period under the entity's equity-based compensation plan net of units withheld to satisfy employee income tax withholding obligations. Stock Issued During Period Value Share Based Compensation, Net of Adjustments Related to Tax withholding Issuance of PAA common units under LTIP, net of units tendered by employees to satisfy tax withholding obligations Partners' Capital Account, Contributions Contributions from noncontrolling interests related to the issuance of common units by subsidiaries Partners' Capital Account, Unit-based Compensation Equity-indexed compensation expense Distribution equivalent right payments made and obligations for future payments. Distribution Equivalent Right Payments Distribution equivalent right payments Partners' Capital, Other Other Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Issuance of Equity by Subsidiary to Noncontrolling Interests Issuance of PNG common units Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Declared Distributions Distributions paid during the period Organization and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Basis of Presentation Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies Acquisitions and Dispositions Business Combination Disclosure [Text Block] Acquisitions and Dispositions Net Income Per Class A Share Earnings Per Share [Text Block] Net Income Per Class A Share Inventory, Linefill and Base Gas and Long-term Inventory 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. Inventory Linefill and Base Gas and Long Term Inventory Disclosure [Text Block] Inventory, Linefill and Base Gas and Long-term Inventory Property and Equipment Property and equipment, useful life Property, Plant and Equipment Disclosure [Text Block] Property and Equipment Goodwill Goodwill Disclosure [Text Block] Goodwill Investments in Unconsolidated Entities Equity Method Investments and Joint Ventures Disclosure [Text Block] Investments in Unconsolidated Entities Other Assets, Net Other Assets Disclosure [Text Block] Other Assets, Net Debt Debt Disclosure [Text Block] Debt Partners' Capital and Distributions Partners' Capital Notes Disclosure [Text Block] Partners' Capital and Distributions