Entity Central Index Key Stock issued during period shares period increase decrease due to share transactions. Stockholders equity period increase decrease due to share transactions. Financial instruments owned exchange traded fund. Financial instruments owned money market mutual fund at fair value. Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Trading assets. Investment owned unrecognized unrealized appreciation depreciation net reclassed. Net asset value per share. Market value per share. Statement Of Financial Position [Abstract] Assets Assets [Abstract] United States Treasury Obligations, at value (cost $1,849,014,340 and $2,403,904,566, respectively) Financial Instruments Owned U S Government And Agency Obligations At Fair Value Affiliated investments, at value (cost $345,916,498 and $131,029,805, respectively) Investments In And Advances To Affiliates At Fair Value Total investments, at value (cost $2,194,930,838 and $2,534,934,371, respectively) Investment Owned At Fair Value Cash held by custodian Cash Receivable for: Receivables From Brokers Dealers And Clearing Organizations [Abstract] Dividends from affiliates Due From Affiliates LME contracts Trading Assets Variation margin Receivables From Clearing Organizations Net unrealized appreciation (depreciation) on Commodity Futures Contracts Investment Owned Unrecognized Unrealized Appreciation Depreciation Net Reclassed Total assets Assets Liabilities Liabilities [Abstract] Payable for: Payables To Broker Dealers And Clearing Organizations [Abstract] Management fee Due To Related Parties Current And Noncurrent Brokerage commissions and fees Commissions Payable To Broker Dealers And Clearing Organizations Total liabilities Liabilities Commitments and Contingencies (Note 10) Commitments And Contingencies Equity Stockholders Equity [Abstract] Shareholder's equity—General Shares General Partners Capital Account Shareholders' equity—Shares Limited Partners Capital Account Total shareholders' equity Stockholders Equity Total liabilities and equity Liabilities And Stockholders Equity General Shares outstanding General Partners Capital Account Units Outstanding Shares outstanding Limited Partners Capital Account Units Outstanding Net asset value per share Net Asset Value Per Share Market value per share Market Value Per Share Investments in and advances to affiliates at cost. Statement [Table] Statement [Table] Legal Entity Legal Entity [Axis] Entity Entity [Domain] Affiliated Investments [Member] Affiliated Entity [Member] Investment Type Investment Type [Axis] Investments Investment Type Categorization [Member] US Treasury Bill Securities [Member] U S Treasury Bill Securities [Member] Statement [Line Items] Statement [Line Items] Investments, cost Investment Owned At Cost Affiliated Investments, at Cost Investments In And Advances To Affiliates At Cost Schedule Of Investments [Abstract] Schedule Of Investments [Table] Schedule Of Investments [Table] US treasury bills zero point five seven zero percentage due April six two thousand seventeen. U.S. Treasury Bills, 0.570% due April 6, 2017 [Member] U S Treasury Bills Zero Point Five Seven Zero Percentage Due April Six Two Thousand Seventeen [Member] US treasury bills zero point seven four five percentage due April twenty seven two thousand seventeen. U.S. Treasury Bills, 0.745% due April 27, 2017 [Member] U S Treasury Bills Zero Point Seven Four Five Percentage Due April Twenty Seven Two Thousand Seventeen [Member] US treasury bills zero point seven two zero percentage due May eighteen two thousand seventeen. U.S. Treasury Bills, 0.720% due May 18, 2017 [Member] U S Treasury Bills Zero Point Seven Two Zero Percentage Due May Eighteen Two Thousand Seventeen [Member] US treasury bills zero point five one five percentage due June one two thousand seventeen. U.S. Treasury Bills, 0.515% due June 1, 2017 [Member] U S Treasury Bills Zero Point Five One Five Percentage Due June One Two Thousand Seventeen [Member] US Treasury Bill Securities [Member] U S Treasury And Government [Member] Exchange-Traded Fund - PowerShares Treasury Collateral Portfolio [Member] Exchange Traded Funds [Member] Money Market Mutual Fund - Premier U.S. Government Money Portfolio - Institutional Class [Member] Money Market Funds [Member] US treasury bills zero point four nine zero percentage due January nineteen two thousand seventeen. U.S. Treasury Bills, 0.490% due January 19, 2017 [Member] U S Treasury Bills Zero Point Four Nine Zero Percentage Due January Nineteen Two Thousand Seventeen [Member] US treasury bills zero point four eight five percentage due January twenty six two thousand seventeen. U.S. Treasury Bills, 0.485% due January 26, 2017 [Member] U S Treasury Bills Zero Point Four Eight Five Percentage Due January Twenty Six Two Thousand Seventeen [Member] US treasury bills zero point four nine zero percentage due March two two thousand seventeen. U.S. Treasury Bills, 0.490% due March 2, 2017 [Member] U S Treasury Bills Zero Point Four Nine Zero Percentage Due March Two Two Thousand Seventeen [Member] US treasury bills zero point five three zero percentage due April six two thousand seventeen. U.S. Treasury Bills, 0.530% due April 6, 2017 [Member] U S Treasury Bills Zero Point Five Three Zero Percentage Due April Six Two Thousand Seventeen [Member] US treasury bills zero point six two five percentage due May eighteen two thousand seventeen. U.S. Treasury Bills, 0.625% due May 18, 2017 [Member] U S Treasury Bills Zero Point Six Two Five Percentage Due May Eighteen Two Thousand Seventeen [Member] Schedule of Investments [Line Items] Schedule Of Investments [Line Items] Percentage of Shareholders' Equity Investment Owned Percent Of Net Assets Value Principal Value Investment Owned Underlying Face Amount At Market Value Affiliated investments, at value Shares Investments In And Advances To Affiliates Balance Shares Total Investments Investment Interest Rate Investment Interest Rate Investment Maturity Date Investment Maturity Date1 Restricted for maintenance margin Good Faith And Margin Deposits With Broker Dealers This element represents the net percentage excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity. Futures [Member] Future [Member] Investment Holding Investment Holding [Axis] Investment Holding Investment Holding [Domain] Corn [Member] Corn [Member] Corn [Member] Soybean. Soybean [Member] Soybean [Member] Wheat commodities. Wheat [Member] Wheat [Member] Gold. Gold [Member] Gold [Member] Silver. Silver [Member] Silver [Member] Brent crude oil. Brent Crude Oil [Member] Brent Crude Oil [Member] Aluminum. Aluminum [Member] Aluminum [Member] Copper. Copper [Member] Copper [Member] Zinc. Zinc [Member] Zinc [Member] Sugar. Sugar [Member] Sugar [Member] Natural gas. Natural Gas [Member] Natural Gas [Member] NY Harbor ULSD. NY Harbor ULSD [Member] N Y Harbor U L S D [Member] RBOB Gasoline. RBOB Gasoline [Member] R B O B Gasoline [Member] WTI crude oil. WTI Crude Oil [Member] W T I Crude Oil [Member] Investment Secondary Categorization Investment Secondary Categorization [Axis] Investments by Secondary Categorization Investments By Secondary Categorization [Domain] CME SWAPS MARKETS (CBOT) [Member] C B T S CME SWAPS MARKETS (COMEX) [Member] C E C S ICE FUTURES EUROPE [Member] I F E U LME CLEAR [Member] L M E C ICE FUTURES U.S. [Member] I F U S CME SWAPS MARKETS (NYMEX) [Member] N Y M S Percentage of Shareholders’ Equity Investment Owned Unrealized Appreciation Depreciation Net Percentage Investment Owned Unrealized Appreciation/ (Depreciation) Tax Basis Of Investments Unrealized Appreciation Depreciation Net Notional Value Number of Contracts Investment Owned Balance Contracts Maturity Date Forward Contract Indexed To Issuers Equity Settlement Date Or Dates Management fee waived. Operating expenses net. Unrealized gain loss on affiliated investments. Income Statement [Abstract] Income Financial Services Revenue [Abstract] Interest Income Interest Income Operating Dividends from Affiliates Dividend Income Operating Total Income Interest And Dividend Income Operating Expenses Operating Expenses [Abstract] Management Fee Professional Fees Brokerage Commissions and Fees Floor Brokerage Exchange And Clearance Fees Interest Expense Interest Expense Total Expenses Operating Expenses Less: Waivers Management Fee Waived Net Expenses Operating Expenses Net Net Investment Income (Loss) Operating Income Loss Net Realized Gain (Loss) on Realized Gain Loss On Marketable Securities Cost Method Investments And Other Investments [Abstract] United States Treasury Obligations Marketable Securities Realized Gain Loss Commodity Futures Contracts Gain Loss On Sale Of Investments Net Realized Gain (Loss) Realized Gain Loss On Marketable Securities Cost Method Investments And Other Investments Net Change in Unrealized Gain (Loss) on Unrealized Gain Loss On Marketable Securities Cost Method Investments And Other Investments [Abstract] United States Treasury Obligations Marketable Securities Unrealized Gain Loss Affiliated Investments Unrealized Gain Loss On Affiliated Investments Commodity Futures Contracts Unrealized Gain Loss On Investments Net Change in Unrealized Gain (Loss) Unrealized Gain Loss On Marketable Securities Cost Method Investments And Other Investments Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts Gain Loss On Investments Net Income (Loss) Net Income Loss Statement Of Stockholders Equity [Abstract] Partner Type Partner Type Of Partners Capital Account [Axis] Partner Type of Partners' Capital Account, Name Partner Type Of Partners Capital Account Name [Domain] General Shares [Member] General Partner [Member] Shares [Member] Limited Partner [Member] Balance - Value Balance - Shares Partners Capital Account Units Purchases of Shares - Value Stock Issued During Period Value New Issues Purchases of Shares - Shares Stock Issued During Period Shares New Issues Redemption of Shares - Value Stock Redeemed Or Called During Period Value Redemption of Shares - Shares Stock Redeemed Or Called During Period Shares Net Increase (Decrease) due to Share Transactions, value Stockholders Equity Period Increase Decrease Due To Share Transactions Net Increase (Decrease) due to Share Transactions, shares Stock Issued During Period Shares Period Increase Decrease Due To Share Transactions Net Income (Loss) Net Income Loss Attributable To Reporting Entity [Abstract] Net Investment Income (Loss) Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts Net Change in Shareholders' Equity, value Stockholders Equity Period Increase Decrease Net Change in Shareholders' Equity, shares Stock Issued During Period Shares Period Increase Decrease Balance - Value Balance - Shares Unrealized gain loss on marketable securities, affiliated investments and derivatives and commodity contracts. Increase (decrease) in variation margin. Operating Cash Flows Direct Method [Abstract] Cash flows from operating activities: Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract] Net Income (Loss) Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Cost of securities purchased Payments For Purchase Of Securities Operating Activities Proceeds from securities sold and matured Proceeds From Sale Of Securities Operating Activities Cost of affiliated investments purchased Payments To Acquire Investments Proceeds from affiliated investments sold Proceeds From Sale Maturity And Collections Of Investments Net accretion of discount on United States Treasury Obligations Depreciation Amortization And Accretion Net Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments Net change in unrealized (gain) loss on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts Unrealized Gain Loss On Marketable Securities Affiliated Investments And Derivatives And Commodity Contracts Change in operating receivables and liabilities: Increase Decrease In Operating Capital [Abstract] Dividends from affiliates Increase Decrease In Dividends Receivable Variation margin Increase Decrease In Variation Margin LME contracts Increase Decrease In Trading Liabilities Management fee Increase Decrease In Accounts Payable Related Parties Brokerage commissions and fees Increase Decrease In Payables To Broker Dealers Net cash provided by (used for) operating activities Net Cash Provided By Used In Operating Activities Continuing Operations Cash flows from financing activities: Net Cash Provided By Used In Financing Activities Continuing Operations [Abstract] Proceeds from purchases of Shares Proceeds From Issuance Of Common Stock Redemption of Shares Payments For Repurchase Of Common Stock Net cash provided by (used for) financing activities Net Cash Provided By Used In Financing Activities Continuing Operations Net change in cash Cash Period Increase Decrease Cash at beginning of period Cash at end of period Supplemental disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid Background and business description. Text Block [Abstract] Background Background And Business Description [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Fund Investment Overview Nature Of Operations Related Party Transactions [Abstract] Service Providers and Related Party Agreements Related Party Transactions Disclosure [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Investments in and Advances to Affiliates Schedule of Investments [Abstract] Investments in Affiliates Investments In And Advances To Affiliates Schedule Of Investments [Text Block] Investments Debt And Equity Securities [Abstract] Financial Instrument Risk Investments In Debt And Marketable Equity Securities And Certain Trading Assets Disclosure [Text Block] Share purchases and redemptions disclosure. Share Purchases and Redemptions Share Purchases And Redemptions Disclosure [Text Block] Equity [Abstract] Profit and Loss Allocations and Distributions Stockholders Equity Note Disclosure [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Earnings Per Share [Abstract] Net Asset Value and Financial Highlights Earnings Per Share [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Use of Estimates Use Of Estimates Financial Instruments and Fair Value Fair Value Of Financial Instruments Policy Policy regarding deposits with commodity broker and custodian. Deposits with Commodity Broker and Custodian Deposits With Commodity Broker And Custodian Policy Policy [Text Block] Investment Transactions and Investment Income Investment Policy [Text Block] Receivable from and payable to shares issued and redeemed. Receivable/ (Payable) for Shares Issued and Redeemed Receivable From And Payable To Shares Issued And Redeemed Policy [Text Block] Receivables and payables for contracts policy. Receivable/ (Payable) For LME Contracts Receivables And Payables For Contracts Policy Policy [Text Block] Income Taxes Income Tax Policy [Text Block] Commodity Futures Contracts Derivatives Policy [Text Block] Brokerage Commissions and Fees Commissions Policy Routine operational administrative and other ordinary expenses policy. Routine Operational, Administrative and Other Ordinary Expenses Routine Operational Administrative And Other Ordinary Expenses Policy Policy [Text Block] Non recurring and unusual fees and expenses. Non-Recurring Fees and Expenses Non Recurring And Unusual Fees And Expenses Policy [Text Block] Summary of the Tiered Valuation Input Levels Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Table [Text Block] Fair Value of Derivative Instruments and Effect of Derivative Instruments on Statements of Income and Expenses Schedule Of Other Derivatives Not Designated As Hedging Instruments Statements Of Financial Performance And Financial Position Location Table [Text Block] Summary of Average Monthly Notional Value of Future Contracts Outstanding Schedule Of Notional Amounts Of Outstanding Derivative Positions Table [Text Block] Offsetting assets and Liabilities. Summary of Gross and Net Amounts of Offsetting Assets and Liabilities Offsetting Assets And Liabilities Table [Text Block] Investments In And Advances To Affiliates Schedule Of Investments [Abstract] Summary of Transactions in, and Earnings from, Investments in PowerShares Treasury Collateral Portfolio Investments In And Advances To Affiliates [Text Block] Net asset value per share table. Schedule of Net Asset Value Per Share Net Asset Value Per Share Table [Text Block] Purchase agreement transaction date Business Acquisition Date Of Acquisition Agreement1 Organization Consolidation And Presentation Of Financial Statements [Abstract] Partners' capital contribution Partners Capital Account Contributions General shares, shares issued Minimum number of baskets of shares that can be purchased. Number of shares issued per basket. Minimum number of Baskets that can be purchased Minimum Number Of Baskets Of Shares That Can Be Purchased Number of shares issued per basket Number Of Shares Issued Per Basket Maximum remaining maturity period of treasury bills for which indexes tracked to measure performance. Maximum remaining maturity of T-Bill ETFs Maximum Remaining Maturity Period Of Treasury Bills For Which Indexes Tracked To Measure Performance Management fee per annum of daily net assets. Management fee percentage per annum of daily net asset Management Fee Per Annum Of Daily Net Assets Managing owner waived fees Fair Value Disclosures [Abstract] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value, Hierarchy Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value Inputs Level1 [Member] Level 2 [Member] Fair Value Inputs Level2 [Member] Level 3 [Member] Fair Value Inputs Level3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] United States Treasury Obligations Exchange-Traded Fund Financial Instruments Owned Exchange Traded Fund Money Market Mutual Fund Financial Instruments Owned Money Market Mutual Fund At Fair Value Commodity Futures Contracts Investment Owned Unrecognized Unrealized Appreciation Depreciation Net Total Investments Financial Instruments Owned At Fair Value Payable for LME contracts Trading Liabilities Derivative Instruments And Hedging Activities Disclosure [Abstract] Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Derivative Instrument Derivative Instrument Risk [Axis] Derivative Contract Derivative Contract Type [Domain] Commodity Futures Contract [Member] Commodity Contract [Member] Hedging Designation Hedging Designation [Axis] Hedging Designation Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Nondesignated [Member] Derivatives, Fair Value [Line Items] Derivatives Fair Value [Line Items] Assets Derivative Fair Value Of Derivative Asset Liabilities Derivative Fair Value Of Derivative Liability Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments Gain Loss [Line Items] Futures contracts, realized gain (loss) Futures contracts, unrealized gain (loss) Average notional value of derivative. Derivative [Table] Derivative [Table] Range Range [Axis] Range Range [Member] Weighted Average [Member] Weighted Average [Member] Derivative [Line Items] Derivative [Line Items] Average Notional Value Average Notional Value Of Derivative Offsetting [Abstract] Offsetting assets and liabilities. Offsetting Assets And Liabilities [Table] Offsetting Assets And Liabilities [Table] Offsetting Assets And Liabilities [Table] Offsetting Assets And Liabilities [Line Items] Offsetting Assets And Liabilities [Line Items] Gross Amounts of Recognized Assets Gross Amounts Offset Assets in the Statement of Financial Condition Derivative Asset Fair Value Gross Liability Net Amounts of Assets Presented in the Statement of Financial Condition Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral Gross Amounts Not Offset in the Statement of Financial Condition - Financial Instruments Assets Derivative Collateral Obligation To Return Securities Gross Amounts Not Offset in the Statement of Financial Condition - Cash Collateral Pledged Assets Derivative Collateral Obligation To Return Cash Assets Net Amount Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral Gross Amounts of Recognized Liabilities Gross Amounts Offset Liabilities in the Statement of Financial Condition Derivative Liability Fair Value Gross Asset Net Amounts of Liabilities Presented in the Statement of Financial Condition Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral Gross Amounts Not Offset In The Statement of Financial Condition - Financial Instruments Liabilities Derivative Collateral Right To Reclaim Securities Gross Amounts Not Offset In The Statement of Financial Condition - Cash Collateral Pledged Liabilities Derivative Collateral Right To Reclaim Cash Liabilities Net Amount Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral Average charges paid to broker per round turn trade maximum. Average charges paid to broker per round-turn trade, maximum Average Charges Paid To Broker Per Round Turn Trade Maximum Investments In And Advances To Affiliates [Table] Investments In And Advances To Affiliates [Table] Investments in and Advances to Affiliates [Line Items] Investments In And Advances To Affiliates [Line Items] Beginning Value Purchases at Cost Investments In And Advances To Affiliates At Fair Value Gross Additions Proceeds from Sales Payments For Proceeds From Investments Change in Unrealized Appreciation (Depreciation) Realized Gain (Loss) Gain On Sale Of Investments Ending Value Dividend Income Investments In And Advances To Affiliates Dividend Or Interest Credited To Income Minimum number of baskets of shares that can be redeemed. Minimum number of Baskets that can be redeemed Minimum Number Of Baskets Of Shares That Can Be Redeemed Distributed earnings Distributed Earnings Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature Loss Contingencies By Nature Of Contingency [Axis] Loss Contingency, Nature Loss Contingency Nature [Domain] Indemnification Agreement [Member] Indemnification Guarantee [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Claims received by fund Loss Contingency New Claims Filed Number Gain (loss) on investments per share. Net investment income (loss) per share. Average net assets to net investment income loss Average net assets to expenses after waivers. Average net assets to expenses prior to waivers. Return at net asset value. Return at market value. Ratio to average net assets. Net Asset Value Fair Value Investments Entities That Calculate Net Asset Value Per Share Percent [Abstract] Net asset value per Share, beginning of period Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts Gain Loss On Investments Per Share Net investment income (loss) Net Investment Income Loss Per Share Net income (loss) Earnings Per Share Basic Net asset value per Share, end of period Market value per Share, beginning of period Market value per Share, end of period Ratio to average Net Assets Ratio To Average Net Assets [Abstract] Net investment income (loss) Average Net Assets To Net Investment Income Loss Expenses, after waivers Average Net Assets To Expenses After Waivers Expenses, prior to waivers Average Net Assets To Expenses Prior To Waivers Total Return, at net asset value Return At Net Asset Value Total Return, at market value Return At Market Value