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 Limited Partners' Capital Account by Class [Axis] Limited Partners Capital Account Class [Domain] Limited Partners' Capital Account, Class [Domain] 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. Shares Class [Member] Class A Shares 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. Shares Class B [Member] Class B Shares 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 Long-Term Assets, Net Goodwill. Balance at end of period Balance at beginning of period Goodwill Equity Method Investments Investments in unconsolidated entities Deferred Income Tax Assets, Net Deferred tax asset Net deferred tax assets 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 long-term assets, net Other long-term 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 and debt issuance costs Senior notes, net of unamortized discounts and debt issuance costs Other Long-term Debt, Noncurrent Noncurrent portion of other long-term debt Other long-term debt, net of unamortized debt issuance costs 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 16) 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 Schedule of Limited Partners' Capital Account by Class [Table] Limited Partners' Capital Account [Line Items] Shares outstanding 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, NGL and natural gas during the period. Sales and Related Revenues Supply and Logistics segment revenues Revenue from the transportation of crude oil and NGL on pipelines, gathering systems, trucks and barges during the period. Pipeline Tariff Activities Trucking and Related Revenues Transportation segment revenues Revenue from the storage, terminalling and throughput services for crude oil, refined products, NGL and natural gas, as well as NGL fractionation and isomerization services and natural gas and condensate processing services during the period. Storage Terminalling Processing and Related Revenues Facilities segment revenues Revenues Revenues Total revenues Total revenues Costs and Expenses [Abstract] COSTS AND EXPENSES Cost of Goods and Services Sold Purchases and related costs Operating Costs and Expenses Field operating costs General and Administrative Expense General and administrative expenses General and administrative expenses Depreciation, Depletion and Amortization 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 $57, $48 and $38, respectively) Interest expense, net Other Nonoperating Income (Expense) 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 Total current income tax expense Deferred Income Tax Expense (Benefit) Deferred income tax expense Deferred income tax expense Total deferred income tax 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 share (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 Other comprehensive loss Total period activity 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 Cash Flow Hedges Including Portion Attributable To Noncontrolling Interest [Member] Derivative Instruments Accumulated Foreign Currency Adjustment Including Portion Attributable To Noncontrolling Interest [Member] Translation Adjustments Accumulated Other Comprehensive Income (Loss), Net of Tax Balance at end of period Balance at beginning of period Net deferred gains/(losses) included in AOCI Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Reclassification adjustments Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, 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: Allocated Share-based Compensation Expense Equity-indexed compensation expense Inventory Write-down Inventory valuation adjustments Charge related to the write-down of inventory The net cash paid (received) for terminated hedging instruments. Net Cash Paid (Received) for Terminated Hedging Instruments Settlement of terminated interest rate hedging instruments Cash received/(paid) in connection with termination of interest rate derivatives 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 and Interest in Affiliates Cash paid in connection with acquisitions, net of cash acquired (Note 7) Cash outflow for capital contributions subsequent to the initial purchase of interest in equity method investments, to fund the entity's portion of development, construction or capital expansion projects of the equity method investees, net of cash received as a return of investment. Capital Contributions to Equity Method Investees Investments in unconsolidated entities (Note 7) Cash contributions to fund development, construction or capital expansion projects Payments to Acquire Property, Plant, and Equipment Additions to property, equipment and other 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 Proceeds from Sale of Productive Assets Proceeds from sales of assets 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 hedged inventory facility. Net Proceeds from (Repayments of) Hedged Inventory Facility Net borrowings/(repayments) under PAA senior secured hedged inventory facility (Note 9) 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 repayments under PAA senior unsecured revolving credit facility (Note 9) 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 repayments under PNG credit agreement Proceeds from (Repayments of) Commercial Paper Net borrowings/(repayments) under PAA commercial paper program (Note 9) Proceeds from (Repayments of) Secured Debt Net borrowings/(repayments) under AAP senior secured revolving credit facility (Note 9) Proceeds from Issuance of Secured Debt Proceeds from AAP term loan (Note 9) Proceeds from Issuance of Senior Long-term Debt Proceeds from the issuance of PAA senior notes (Note 9) Repayments of Senior Debt Repayments of PAA senior notes (Note 9) Repayments of senior notes Proceeds from Noncontrolling Interests Net proceeds from the sale of common units by subsidiaries (Note 10) Proceeds from Contributions from Affiliates Contributions from noncontrolling interests related to the sale 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 10) 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 10) Distribution Made to Limited Partner, Cash Distributions Paid Distributions paid to Class A shareholders (Note 10) Distributions paid to Class A shareholders Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid Distributions paid to members (Note 10) Distributions paid during the period Payments of Ordinary Dividends, Noncontrolling Interest Distributions paid to noncontrolling interests (Note 10) 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) Increase (Decrease) in Partners' Capital [Roll Forward] Increase (Decrease) in Partners' Capital Activity for Class A shares and Class B shares 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 10) Stock Issued During Period, Value, New Issues Issuance of Class A shares to the public, net of offering and other costs (Note 10) 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 10) 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 12) 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 10) Noncontrolling Interest, Increase from Subsidiary Equity Issuance Sale of common units by subsidiaries Partners' Capital, Other Other Organization and Basis of Consolidation and Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Basis of Consolidation and Presentation Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies 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, 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 Long-Term Assets, Net Other Assets Disclosure [Text Block] Other Long-Term Assets, Net Debt Debt Disclosure [Text Block] Debt Partners' Capital and Distributions Partners' Capital Notes Disclosure [Text Block] Partners' Capital and Distributions Derivatives and Risk Management Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivatives and Risk Management Activities Income Taxes Income Tax Disclosure [Text Block] Income Taxes Major Customers and Concentration of Credit Risk Concentration Risk Disclosure [Text Block] Major Customers and Concentration of Credit Risk Related Party Transactions Related Party Transactions Disclosure [Text Block] Related Party Transactions Equity-Indexed Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Equity-Indexed Compensation Plans Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Quarterly Financial Data (Unaudited) Operating Segments