PowerShares DB Multi-Sector Commodity Trust 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	DBB
Entity Registrant Name	POWERSHARES DB BASE METALS FUND
Entity Central Index Key	1,383,084
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		17,600,000
Entity Public Float			$ 209,664,000

Statements of Financial Conditi

Statements of Financial Condition - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Assets
United States Treasury Obligations, at value (cost $244,424,302 and $252,672,685, respectively)	$ 244,408,079	$ 252,671,516
Affiliated Investments, at value (cost $39,110,095 and $19,276,827, respectively)	39,094,237	19,276,827
Other investments:
Net unrealized appreciation on LME Commodity Futures Contracts	31,489,170
Net unrealized appreciation (depreciation) on Commodity Futures Contracts		12,495,905
Receivable for:
Dividends from affiliates	17,523	4,928
Total assets	315,009,009	284,449,176
Other investments:
LME Commodity Futures Contracts payable	731,031	129,711
Payable for:
Management fees	182,156	179,015
Brokerage commissions and fees	4,561	4,561
Total liabilities	917,748	313,287
Commitments and Contingencies (Note 10)
Equity
Shareholder's equity—General Shares	776	598
Shareholders' equity—Shares	314,090,485	284,135,291
Total shareholders' equity	314,091,261	284,135,889
Total liabilities and equity	$ 315,009,009	$ 284,449,176
General Shares outstanding	40	40
Shares outstanding	16,200,000	19,000,000
Net asset value per share	$ 19.39	$ 14.95
Market value per share	$ 19.43	$ 14.91

Statements of Financial Condit3

Statements of Financial Condition (Parenthetical) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Investments, cost	$ 283,534,397	$ 271,949,512
US Treasury Bill Securities [Member]
Investments, cost	244,424,302	252,672,685
Affiliated Investments [Member]
Affiliated Investments, at Cost	$ 39,110,095	$ 19,276,827

Schedule of Investments - Treas

Schedule of Investments - Treasury Bills and Money Market Fund - USD ($)		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Schedule Of Investments [Line Items]
Investments, cost		$ 283,534,397		$ 271,949,512
Percentage of Shareholders' Equity		90.26%		95.71%
Value		$ 244,408,079		$ 252,671,516
Affiliated investments, at value		39,094,237		19,276,827
Total Investments in Securities		283,502,316		271,948,343
Affiliated Investments [Member]
Schedule Of Investments [Line Items]
Affiliated Investments, at Cost		$ 39,110,095		19,276,827
Percentage of Shareholders' Equity		12.45%
Affiliated investments, at value		$ 39,094,237
U.S. Treasury Bills, 1.180% due January 4, 2018 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[1]	1.18%
Investment Maturity Date	[1]	Jan. 4, 2018
Percentage of Shareholders' Equity	[1]	14.01%
Value	[1]	$ 43,997,241
Principal Value	[1]	$ 44,000,000
U.S. Treasury Bills, 1.245% due January 18, 2018 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[1]	1.245%
Investment Maturity Date	[1]	Jan. 18, 2018
Percentage of Shareholders' Equity	[1]	14.95%
Value	[1]	$ 46,974,228
Principal Value	[1]	$ 47,000,000
U.S. Treasury Bills, 1.285% due February 22, 2018 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[1]	1.285%
Investment Maturity Date	[1]	Feb. 22, 2018
Percentage of Shareholders' Equity	[1]	16.21%
Value	[1]	$ 50,908,965
Principal Value	[1]	$ 51,000,000
U.S. Treasury Bills, 1.285% due March 1, 2018 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[1],[2]	1.285%
Investment Maturity Date	[1],[2]	Mar. 1, 2018
Restricted for maintenance margin	[1],[2]	$ 12,972,700
Percentage of Shareholders' Equity	[1],[2]	13.34%
Value	[1],[2]	$ 41,914,233
Principal Value	[1],[2]	$ 42,000,000
U.S. Treasury Bills, 1.450% due June 7, 2018 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[1]	1.45%
Investment Maturity Date	[1]	Jun. 7, 2018
Percentage of Shareholders' Equity	[1]	19.30%
Value	[1]	$ 60,613,412
Principal Value	[1]	61,000,000
United States Treasury Obligations [Member]
Schedule Of Investments [Line Items]
Investments, cost		$ 244,424,302	[1]	$ 252,672,685	[3]
Percentage of Shareholders' Equity		77.81%	[1]	88.93%	[3]
Value		$ 244,408,079	[1]	$ 252,671,516	[3]
Exchange-Traded Fund - PowerShares Treasury Collateral Portfolio [Member] | Affiliated Investments [Member]
Schedule Of Investments [Line Items]
Affiliated Investments, at Cost	[4]	$ 16,006,371
Percentage of Shareholders' Equity	[4]	5.09%
Affiliated investments, at value	[4]	$ 15,990,513
Shares	[4]	151,900
Money Market Mutual Fund - Invesco Premier U.S. Government Money Portfolio - Institutional Class [Member] | Affiliated Investments [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate		1.15%	[5]	0.41%	[6]
Affiliated Investments, at Cost		$ 23,103,724	[5]	$ 19,276,827	[6]
Percentage of Shareholders' Equity		7.36%	[5]	6.78%	[6]
Affiliated investments, at value		$ 23,103,724	[5]	$ 19,276,827	[6]
Shares		23,103,724	[5]	19,276,827	[6]
U.S. Treasury Bills, 0.490% due January 19, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3]			0.49%
Investment Maturity Date	[3]			Jan. 19, 2017
Percentage of Shareholders' Equity	[3]			4.93%
Value	[3]			$ 13,997,466
Principal Value	[3]			$ 14,000,000
U.S. Treasury Bills, 0.485% due January 26, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3],[7]			0.485%
Investment Maturity Date	[3],[7]			Jan. 26, 2017
Restricted for maintenance margin	[7]			$ 31,990,400
Percentage of Shareholders' Equity	[3],[7]			17.59%
Value	[3],[7]			$ 49,986,850
Principal Value	[3],[7]			$ 50,000,000
U.S. Treasury Bills, 0.475% due February 2, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3]			0.475%
Investment Maturity Date	[3]			Feb. 2, 2017
Percentage of Shareholders' Equity	[3]			1.76%
Value	[3]			$ 4,998,265
Principal Value	[3]			$ 5,000,000
U.S. Treasury Bills, 0.490% due March 2, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3]			0.49%
Investment Maturity Date	[3]			Mar. 2, 2017
Percentage of Shareholders' Equity	[3]			15.12%
Value	[3]			$ 42,967,105
Principal Value	[3]			$ 43,000,000
U.S. Treasury Bills, 0.530% due April 6, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3]			0.53%
Investment Maturity Date	[3]			Apr. 6, 2017
Percentage of Shareholders' Equity	[3]			15.12%
Value	[3]			$ 42,942,036
Principal Value	[3]			$ 43,000,000
U.S. Treasury Bills, 0.625% due May 18, 2017 [Member]
Schedule Of Investments [Line Items]
Investment Interest Rate	[3]			0.625%
Investment Maturity Date	[3]			May 18, 2017
Percentage of Shareholders' Equity	[3]			34.41%
Value	[3]			$ 97,779,794
Principal Value	[3]			$ 98,000,000
[1]	Security may be traded on a discount basis. The interest rate shown represents the discount rate at the most recent auction date of the security prior to period end.
[2]	United States Treasury Obligations of $12,972,700 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.
[3]	Security may be traded on a discount basis. The interest rate shown represents the discount rate at the most recent auction date of the security prior to year end.
[4]	Affiliated company. The security and the Fund are affiliated by having the same investment adviser. See Note 8.
[5]	The security and the Fund are advised by wholly-owned subsidiaries of Invesco Ltd. and are therefore considered to be affiliated. The rate shown is the 7-day SEC standardized yield as of December 31, 2017.
[6]	The security and the Fund are advised by wholly-owned subsidiaries of Invesco Ltd. and are therefore considered to be affiliated. The rate shown is the 7-day SEC standardized yield as of December 31, 2016.
[7]	United States Treasury Obligations of $31,990,400 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.

Schedule of Investments - Futur

Schedule of Investments - Futures Contracts		12 Months Ended
		Dec. 31, 2017USD ($)Contract		Dec. 31, 2016USD ($)Contract
Schedule Of Investments [Line Items]
Value		$ 283,502,316		$ 271,948,343
Total Commodity Futures Contracts Purchased [Member] | Long [Member]
Schedule Of Investments [Line Items]
Value	[1]	31,489,170
Unrealized Appreciation (Depreciation)		$ 31,489,170	[1]	$ 12,495,905	[2]
Total Commodity Futures Contracts Purchased [Member] | LME CLEAR [Member] | Long [Member] | Aluminum [Member]
Schedule Of Investments [Line Items]
Number of Contracts | Contract		1,860		2,118
Expiration Date		Oct. 31, 2018		Oct. 31, 2017
Notional Value		$ 106,903,500		$ 90,319,463
Value	[1]	6,848,032
Unrealized Appreciation (Depreciation)		$ 6,848,032	[1]	$ (674,731)	[2]
Total Commodity Futures Contracts Purchased [Member] | LME CLEAR [Member] | Long [Member] | Copper [Member]
Schedule Of Investments [Line Items]
Number of Contracts | Contract		583		709
Expiration Date		Feb. 28, 2018		Feb. 28, 2017
Notional Value		$ 105,442,838		$ 98,023,681
Value	[1]	20,057,969
Unrealized Appreciation (Depreciation)		$ 20,057,969	[1]	$ 10,127,800	[2]
Total Commodity Futures Contracts Purchased [Member] | LME CLEAR [Member] | Long [Member] | Zinc [Member]
Schedule Of Investments [Line Items]
Number of Contracts | Contract		1,265		1,494
Expiration Date		Jan. 31, 2019		Dec. 31, 2017
Notional Value		$ 101,832,500		$ 95,849,437
Value	[1]	4,583,169
Unrealized Appreciation (Depreciation)		$ 4,583,169	[1]	$ 3,042,836	[2]
[1]	Unrealized Appreciation (Depreciation) and Value are presented above, net by contract.
[2]	Unrealized Appreciation (Depreciation) is presented above, net by contract.

Statements of Income and Expens

Statements of Income and Expenses - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Interest Income	$ 1,790,354	$ 448,660	$ 74,872
Dividends from Affiliates	230,312	16,905
Total Income	2,020,666	465,565	74,872
Expenses
Management Fee	2,075,308	1,211,820	1,327,630
Brokerage Commissions and Fees	90,108	175,794	158,402
Interest Expense		39,878	111,932
Total Expenses	2,165,416	1,427,492	1,597,964
Less: Waivers	(42,832)	(8,810)	0
Net Expenses	2,122,584	1,418,682	1,597,964
Net Investment Income (Loss)	(101,918)	(953,117)	(1,523,092)
Net Realized Gain (Loss) on
United States Treasury Obligations	(438)	5,903	3,819
Commodity Futures Contracts	52,294,017	10,296,432	(55,724,875)
Net Realized Gain (Loss)	52,293,579	10,302,335	(55,721,056)
Net Change in Unrealized Gain (Loss) on
United States Treasury Obligations	(15,054)	(10,429)	7,629
Affiliated Investments	(15,858)
Commodity Futures Contracts	18,993,265	26,387,124	(417,044)
Net Change in Unrealized Gain (Loss)	18,962,353	26,376,695	(409,415)
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	71,255,932	36,679,030	(56,130,471)
Net Income (Loss)	$ 71,154,014	$ 35,725,913	$ (57,653,563)

Statement of Changes in Shareho

Statement of Changes in Shareholders' Equity - USD ($)	Total	General Shares [Member]	Shares [Member]
Balance - Value at Dec. 31, 2014	$ 220,647,504	$ 640	$ 220,646,864
Balance - Shares at Dec. 31, 2014		40	13,800,000
Purchases of Shares - Value	145,005,969		$ 145,005,969
Purchases of Shares - Shares			9,400,000
Redemption of Shares - Value	(194,016,598)		$ (194,016,598)
Redemption of Shares - Shares			(13,600,000)
Net Increase (Decrease) due to Share Transactions, value	(49,010,629)		$ (49,010,629)
Net Increase (Decrease) due to Share Transactions, shares			(4,200,000)
Net Income (Loss)
Net Investment Income (Loss)	(1,523,092)	$ (4)	$ (1,523,088)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(55,721,056)	(160)	(55,720,896)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(409,415)	(1)	(409,414)
Net Income (Loss)	(57,653,563)	(165)	(57,653,398)
Net Change in Shareholders' Equity, value	(106,664,192)	(165)	$ (106,664,027)
Net Change in Shareholders' Equity, shares			(4,200,000)
Balance - Value at Dec. 31, 2015	113,983,312	$ 475	$ 113,982,837
Balance - Shares at Dec. 31, 2015		40	9,600,000
Purchases of Shares - Value	248,146,420		$ 248,146,420
Purchases of Shares - Shares			18,200,000
Redemption of Shares - Value	(113,719,756)		$ (113,719,756)
Redemption of Shares - Shares			(8,800,000)
Net Increase (Decrease) due to Share Transactions, value	134,426,664		$ 134,426,664
Net Increase (Decrease) due to Share Transactions, shares			9,400,000
Net Income (Loss)
Net Investment Income (Loss)	(953,117)	$ (3)	$ (953,114)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	10,302,335	35	10,302,300
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	26,376,695	91	26,376,604
Net Income (Loss)	35,725,913	123	35,725,790
Net Change in Shareholders' Equity, value	170,152,577	123	$ 170,152,454
Net Change in Shareholders' Equity, shares			9,400,000
Balance - Value at Dec. 31, 2016	284,135,889	$ 598	$ 284,135,291
Balance - Shares at Dec. 31, 2016		40	19,000,000
Purchases of Shares - Value	101,698,521		$ 101,698,521
Purchases of Shares - Shares			6,000,000
Redemption of Shares - Value	(142,897,163)		$ (142,897,163)
Redemption of Shares - Shares			(8,800,000)
Net Increase (Decrease) due to Share Transactions, value	(41,198,642)		$ (41,198,642)
Net Increase (Decrease) due to Share Transactions, shares			(2,800,000)
Net Income (Loss)
Net Investment Income (Loss)	(101,918)		$ (101,918)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	52,293,579	$ 131	52,293,448
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	18,962,353	47	18,962,306
Net Income (Loss)	71,154,014	178	71,153,836
Net Change in Shareholders' Equity, value	29,955,372	178	$ 29,955,194
Net Change in Shareholders' Equity, shares			(2,800,000)
Balance - Value at Dec. 31, 2017	$ 314,091,261	$ 776	$ 314,090,485
Balance - Shares at Dec. 31, 2017		40	16,200,000

Statements of Cash Flows

Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Cash flows from operating activities:
Net Income (Loss)		$ 71,154,014	$ 35,725,913		$ (57,653,563)
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Cost of securities purchased		(746,953,251)	(655,227,831)		(839,000,652)
Proceeds from securities sold and matured		756,990,870	538,985,029		917,099,129
Cost of affiliated investments purchased		(431,642,566)	(157,619,562)
Proceeds from affiliated investments sold		411,809,298	138,342,735
Net accretion of discount on United States Treasury Obligations		(1,789,674)	(448,660)		(74,872)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments		438	(5,903)		(3,819)
Net change in unrealized (gain) loss on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts		(18,962,353)	(26,376,695)		409,415
Change in operating assets and liabilities:
Dividends from affiliates		(12,595)	(4,928)
LME Commodity Futures Contracts		601,320	(12,743,413)		5,768,874
Management fee		3,141	96,170		(48,080)
Brokerage commissions and fees			(446)		372
Net cash provided by (used for) operating activities		41,198,642	(139,277,591)		26,496,804
Cash flows from financing activities:
Proceeds from purchases of Shares		101,698,521	248,146,420		145,005,969
Redemption of Shares		(142,897,163)	(113,719,756)		(194,016,598)
Net cash provided by (used for) financing activities		$ (41,198,642)	134,426,664		(49,010,629)
Net change in cash			(4,850,927)		(22,513,825)
Cash at beginning of period			4,850,927	[1]	27,364,752	[2]
Cash at end of period	[1]				4,850,927
Supplemental disclosure of cash flow information
Cash paid for interest			$ 39,878		$ 111,932
[1]	Cash at December 31, 2017, 2016 and 2015 reflects cash held by the Custodian
[2]	Cash at December 31, 2014 reflects cash held by the Predecessor Commodity Broker.

Organization

Organization	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Note 1 - Organization PowerShares DB Base Metals Fund (the “Fund”), a separate series of PowerShares DB Multi-Sector Commodity Trust (the “Trust”), was formed as a Delaware statutory trust organized in seven separate series was formed on August 3, 2006. The term of the Fund is perpetual (unless terminated earlier in certain circumstances) as provided for in the Fifth Amended and Restated Declaration of Trust and Trust Agreement of the Trust, as amended (the “Trust Agreement”). The Fund has an unlimited number of shares authorized for issuance. Invesco PowerShares Capital Management LLC (“Invesco”) has served as the managing owner (the “Managing Owner”), commodity pool operator and commodity trading advisor of the Trust and the Fund since February 23, 2015 (the “Closing Date”). Prior to the Closing Date, a different company served the Fund in those capacities (the “Predecessor Managing Owner”). The Predecessor Managing Owner seeded the Fund with a capital contribution of $1,000 in exchange for 40 general shares (the “General Shares”) of the Fund. The General Shares were sold to the Managing Owner by the Predecessor Managing Owner pursuant to the terms of the asset purchase agreement entered into with DB US Financial Markets Holding Corporation. The fiscal year end of the Fund is December 31st. The Fund seeks to track changes, whether positive or negative, in the level of the DBIQ Optimum Yield Industrial Metals Index Excess Return™ (the “Index”) over time, plus the excess, if any, of the sum of the Fund’s interest income from its holdings of United States Treasury Obligations, dividends from its holdings in money market mutual funds (affiliated or otherwise) and dividends or distributions of capital gains from its holdings of T-Bill ETFs (as defined below) over the expenses of the Fund. The Fund invests in futures contracts in an attempt to track its Index. The Index is intended to reflect the change in market value of the base metals sector. The commodities comprising the Index are aluminum, zinc and copper—Grade A (each an “Index Commodity”, and collectively, the “Index Commodities”). The Fund may invest directly in United States Treasury Obligations. The Fund may also gain exposure to United States Treasury Obligations through investments in exchange-traded funds (“ETFs”) (affiliated or otherwise) that track indexes that measure the performance of United States Treasury Obligations with a maximum remaining maturity of up to 12 months (“T-Bill ETFs”). The Fund invests in United States Treasury Obligations, money market mutual funds and T-Bill ETFs (affiliated or otherwise), if any, for margin and/or cash management purposes. The Commodity Futures Trading Commission (the “CFTC”) and certain futures exchanges impose position limits on futures contracts that reference Index Commodities (the “Index Contracts”). As the Fund approaches or reaches position limits with respect to an Index Commodity, the Fund may commence investing in Index Contracts that reference other Index Commodities. In those circumstances, the Fund may also trade in futures contracts based on commodities other than Index Commodities that the Managing Owner reasonably believes tend to exhibit trading prices that correlate with an Index Contract. In addition, the Managing Owner may determine to invest in other futures contracts if at any time it is impractical or inefficient to gain full or partial exposure to an Index Commodity through the use of Index Contracts. These other futures contracts may or may not be based on an Index Commodity. When they are not, the Managing Owner may seek to select futures contracts that it reasonably believes tend to exhibit trading prices that correlate with an Index Contract. The Fund offers common units of beneficial interest (the “Shares”) only to certain eligible financial institutions (the “Authorized Participants”) in one or more blocks of 200,000 Shares, called a Basket. The Fund commenced investment operations on January 3, 2007. The Fund commenced trading on the American Stock Exchange (which became the NYSE Alternext US LLC) on January 5, 2007 and, since November 25, 2008, has been listed on the NYSE Arca, Inc. (the “NYSE Arca”). This Annual Report (the “Report”) covers the years ended December 31, 2017, 2016 and 2015. The Fund’s performance information from inception up to and excluding the Closing Date is a reflection of the performance associated with the Predecessor Managing Owner. The Managing Owner has served as managing owner of the Fund since the Closing Date, and the Fund’s performance information since the Closing Date is a reflection of the performance associated with the Managing Owner. Past performance of the Fund is not necessarily indicative of future performance.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2 - Summary of Significant Accounting Policies A. The financial statements of the Fund have been prepared using accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain reclassifications have been made to prior years’ financial statements to conform to the current year presentation. The Fund has determined that it meets the definition of an investment company and has prepared the financial statements in conformity with U.S. GAAP for investment companies in conformity with accounting and reporting guidance of the Financial Accounting Standards Board Accounting Standards Codification Topic 946, Financial Services Investment Companies B. Accounting Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates by a significant amount. In addition, the Fund monitors for material events or transactions that may occur or become known after the period-end date and before the date the financial statements are released to print. C. Investment Valuations Investments in open-end and closed-end registered investment companies that do not trade on an exchange are valued at the end-of-day net asset value (“NAV”) per share. Investments in open-end and closed-end registered investment companies that trade on an exchange are valued at the last sales price or official closing price as of the close of the customary trading session on the exchange where the security is principally traded. United States Treasury Obligations are fair valued using an evaluated quote provided by an independent pricing service. Evaluated quotes provided by the pricing service may be determined without exclusive reliance on quoted prices, and may reflect appropriate factors such as developments related to specific securities, yield, quality, type of issue, coupon rate, maturity, individual trading characteristics and other market data. All debt obligations involve some risk of default with respect to interest and/or principal payments. Futures contracts are valued at the final settlement price set by an exchange on which they are principally traded. When market closing prices are not available, the Managing Owner may value an asset of the Fund pursuant to policies the Managing Owner has adopted, which are consistent with normal industry standards. D. Investment Transactions and Investment Income Investment transactions are accounted for on a trade date basis. Realized gains or losses from the sale or disposition of securities or derivatives are determined on a specific identification basis and recognized in the Statements of Income and Expenses in the period in which the contract is closed or the sale or disposition occurs, respectively. Interest income on United States Treasury Obligations is recognized on an accrual basis when earned. Premiums and discounts are amortized or accreted over the life of the United States Treasury Obligations. Dividend income (net of withholding tax, if any) is recorded on the ex-dividend date. E. Profit and Loss Allocations and Distributions Pursuant to the Trust Agreement, income and expenses are allocated pro rata pro rata No distributions were paid for the years ended December 31, 2017, 2016 and 2015. F. Routine Operational, Administrative and Other Ordinary Expenses Upon assuming the role of Managing Owner on the Closing Date, the Managing Owner assumed all routine operational, administrative and other ordinary expenses of the Fund, including, but not limited to, computer services, the fees and expenses of the Trustee, legal and accounting fees and expenses, tax preparation expenses, filing fees and printing, mailing and duplication costs. Prior to that date, the Predecessor Managing Owner assumed all routine operational, administrative and other ordinary expenses of the Fund. The Fund does not reimburse the Managing Owner for the routine operational, administrative and other ordinary expenses of the Fund. Accordingly, such expenses are not reflected in the Statements of Income and Expenses of the Fund. G. Non-Recurring Fees and Expenses The Fund pays all non-recurring and unusual fees and expenses, if any, of itself, as determined by the Managing Owner. Non-recurring and unusual fees and expenses include fees and expenses, such as legal claims and liabilities, litigation costs, indemnification expenses or other non-routine expenses. Non-recurring and unusual fees and expenses, by their nature, are unpredictable in terms of timing and amount. For the years ended December 31, 2017, 2016 and 2015, the Fund did not incur such expenses. H. Brokerage Commissions and Fees The Fund incurs all brokerage commissions, including applicable exchange fees, National Futures Association (“NFA”) fees, give-up fees, pit brokerage fees and other transaction related fees and expenses charged in connection with trading activities by the Commodity Broker (as defined below). These costs are recorded as Brokerage Commissions and Fees in the Statements of Income and Expenses. The Commodity Broker’s brokerage commissions and trading fees are determined on a contract-by-contract basis. On average, total charges paid to the Commodity Broker, as applicable were less than $19.00, $19.00 and $19.00 per round-turn trade during the years ended December 31, 2017, 2016 and 2015, respectively. I. Income Taxes The Fund is classified as a partnership for U.S. federal income tax purposes. Accordingly, the Fund will generally not incur U.S. federal income taxes. No provision for federal, state, and local income taxes has been made in the accompanying financial statements, as investors are individually liable for income taxes, if any, on their allocable share of the Fund’s income, gain, loss, deductions and other items. The Managing Owner has reviewed all of the Fund’s open tax years and major jurisdictions and concluded that there is no tax liability resulting from unrecognized tax benefits relating to uncertain tax positions taken or expected to be taken in future tax returns. The Fund is also not aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. The major tax jurisdiction for the Fund and the earliest tax year subject to examination: United States, 2014. J. Commodity Futures Contracts The Fund utilizes derivative instruments to achieve its investment objective. A commodity futures contract is an agreement between counterparties to purchase or sell a specified underlying commodity for a specified price, or to pay or receive a cash amount based on the value of an index or other reference instrument, at a future date. Initial margin deposits required upon entering into futures contracts are satisfied by the segregation of specific securities or cash as collateral with the Commodity Broker. During the period that the commodity futures contracts are open, changes in the value of the contracts are recognized as unrealized gains or losses by recalculating the value of the contracts on a daily basis. Subsequent or variation margin payments are received or made on non-LME commodity futures contracts depending upon whether unrealized gains or losses are incurred. These amounts are reflected as a receivable or payable on the Statements of Financial Condition. For LME contracts, subsequent or variation margin payments are not made and the value of the contracts is presented as net unrealized appreciation (depreciation) on the Statements of Financial Condition. When LME or non-LME contracts are closed or expire, the Fund recognizes a realized gain or loss equal to the difference between the proceeds from, or cost of, the closing transaction and the Fund’s basis in the contract. Realized gains (losses) and changes in unrealized appreciation (depreciation) on open positions are determined on a specific identification basis and recognized in the Statements of Income and Expenses in the period in which the contract is closed or the changes occur, respectively. K. Receivable/(Payable) for LME Contracts The Fund trades aluminum, copper and zinc commodity futures contracts on the LME. For settlement of futures contracts traded on the LME, cash is not transferred until the settled futures contracts expire. As of December 31, 2017, the Fund had a payable to the Commodity Broker of $731,031, related to net realized losses on LME contracts, which have been closed out but for which the contract was not yet expired. As of December 31, 2016, the Fund had a payable to the Commodity Broker of $129,711, related to net realized losses on LME contracts which have been closed out but for which the contract has not yet expired.

Financial Instrument Risk

Financial Instrument Risk	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Financial Instrument Risk	Note 3 - Financial Instrument Risk In the normal course of its business, the Fund is a party to financial instruments with off-balance sheet risk. The term “off-balance sheet risk” refers to an unrecorded potential liability that, even though it does not appear on the balance sheet, may result in a future obligation or loss in excess of the amounts shown on the Statements of Financial Condition. The financial instruments used by the Fund are commodity futures contracts, whose values are based upon an underlying asset and generally represent future commitments that have a reasonable possibility of being settled in cash or through physical delivery. The financial instruments are traded on an exchange and are standardized contracts. Market risk is the potential for changes in the value of the financial instruments traded by the Fund due to market changes, including fluctuations in commodity prices. In entering into these futures contracts, there exists a market risk that such futures contracts may be significantly influenced by adverse market conditions, resulting in such futures contracts being less valuable. If the markets should move against all of the futures contracts at the same time, the Fund could experience substantial losses. Credit risk is the possibility that a loss may occur due to the failure of the Commodity Broker and/or clearing house to perform according to the terms of a futures contract. Credit risk with respect to exchange-traded instruments is reduced to the extent that an exchange or clearing organization acts as a counterparty to the transactions. The Commodity Broker, when acting as the Fund’s futures commission merchant in accepting orders for the purchase or sale of domestic futures contracts, is required by CFTC regulations to separately account for and segregate as belonging to the Fund all assets of the Fund relating to domestic futures trading and the Commodity Broker is not allowed to commingle such assets with other assets of the Commodity Broker. In addition, CFTC regulations also require the Commodity Broker to hold in a secure account assets of the Fund related to foreign futures trading. The Fund’s risk of loss in the event of counterparty default is typically limited to the amounts recognized in the Statements of Financial Condition and not represented by the futures contract or notional amounts of the instruments. The Fund has not utilized, nor does it expect to utilize in the future, special purpose entities to facilitate off-balance sheet financing arrangements and has no loan guarantee arrangements or off-balance sheet arrangements of any kind, other than agreements entered into in the normal course of business noted above.

Service Providers and Related P

Service Providers and Related Party Agreements	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Service Providers and Related Party Agreements	Note 4 – Service Providers and Related Party Agreements The Trustee Under the Trust Agreement, Wilmington Trust Company, the trustee of the Trust and the Fund (the “Trustee”), has the power and authority to execute and file certificates as required by the Delaware Statutory Trust Act and to accept service of process on the Fund in the State of Delaware. The Managing Owner has the exclusive management and control of all aspects of the business of the Trust and the Fund. The Trustee will serve in that capacity until such time as the Managing Owner removes the Trustee or the Trustee resigns and a successor is appointed by the Managing Owner. The Trustee will have no duty or liability to supervise or monitor the performance of the Managing Owner, nor will the Trustee have any liability for the acts or omissions of the Managing Owner. The Managing Owner The Managing Owner serves as the Fund’s commodity pool operator, commodity trading advisor and managing owner. The Fund pays the Managing Owner a management fee, monthly in arrears, in an amount equal to 0.75% per annum of the daily NAV of the Fund (the “Management Fee”). The Fund, for cash management purposes, invests in money market mutual funds and/or T-Bill ETFs that are managed by affiliates of the Managing Owner. The indirect portion of the management fee that the Fund incurs through such investments is in addition to the Management Fee paid to the Managing Owner. The Managing Owner has contractually agreed to waive the fees that it receives in an amount equal to the indirect management fees that the Fund incurs through its investments in affiliated money market mutual funds and/or affiliated T-Bill ETFs indefinitely. The Managing Owner waived fees of $42,832 and $8,810 for the years ended December 31, 2017 and 2016, respectively. The Managing Owner did not waive fees for the year ended December 31, 2015. The Distributor Effective June 20, 2016, Invesco Distributors, Inc. (the “Distributor”) became distributor and began providing certain distribution services to the Fund. Pursuant to the Distribution Services Agreement among the Managing Owner, the Fund and the Distributor, the Distributor assists the Managing Owner and the Fund’s administrator, The Bank of New York Mellon with certain functions and duties relating to distribution and marketing services to the Fund including reviewing and approving marketing materials. Prior to June 20, 2016, ALPS Distributors, Inc. provided distribution services to the Fund. The Managing Owner pays the Distributor a distribution fee out of the Management Fee. The Commodity Broker Morgan Stanley & Co. LLC, a Delaware limited liability company, serves as the Fund’s futures clearing broker (the “Commodity Broker”). The Commodity Broker is registered with the CFTC as a futures commission merchant and is a member of the NFA in such capacity. A variety of executing brokers execute futures transactions on behalf of the Fund. Such executing brokers give-up all such transactions to the Commodity Broker. In its capacity as clearing broker, the Commodity Broker may execute or receive transactions executed by others and clears all of the Fund’s futures transactions and performs certain administrative and custodial services for the Fund. The Commodity Broker is responsible, among other things, for providing periodic accountings of all dealings and actions taken by the Fund during the reporting period, together with an accounting of all securities, cash or other indebtedness or obligations held by it or its nominees for or on behalf of the Fund. The Administrator, Custodian and Transfer Agent The Bank of New York Mellon (the “Administrator” and “Custodian”) is the administrator, custodian and transfer agent of the Fund. The Fund and the Administrator have entered into separate administrative, custodian, transfer agency and service agreements (collectively referred to as the “Administration Agreement”). Pursuant to the Administration Agreement, the Administrator performs or supervises the performance of services necessary for the operation and administration of the Fund (other than making investment decisions), including receiving and processing orders from Authorized Participants to create and redeem Baskets, NAV calculations, accounting and other fund administrative services. The Administrator maintains certain financial books and records, including: Basket creation and redemption books and records, fund accounting records, ledgers with respect to assets, liabilities, capital, income and expenses, the registrar, transfer journals and related details, and trading and related documents received from the Commodity Broker. The Managing Owner pays the Administrator fees for its services out of the Management Fee. During the three-day period from February 24, 2015 to February 26, 2015, the Fund transferred $31,802,760 of cash and $155,996,427 of United States Treasury Obligations from the Predecessor Commodity Broker to the Custodian. Additionally, during that same three-day period, the Fund transferred all of its open positions of commodity futures contracts from the Predecessor Commodity Broker to the Commodity Broker and $51,994,800 of United States Treasury Obligations from the Custodian to the Commodity Broker to satisfy maintenance margin requirements. The cumulative amount of cash transferred to the Commodity Broker as of December 31, 2015 approximates the net unrealized appreciation (depreciation) on commodity futures contracts. Index Sponsor The Managing Owner, on behalf of the Fund, has appointed Deutsche Bank Securities Inc. to serve as the index sponsor (the “Index Sponsor”). The Index Sponsor calculates and publishes the daily index levels and the indicative intraday index levels. Additionally, the Index Sponsor also calculates the indicative value per Share of the Fund throughout each business day. The Managing Owner pays the Index Sponsor a licensing fee and an index services fee out of the Management Fee for performing its duties.

Deposits with Commodity Broker

Deposits with Commodity Broker and Custodian	12 Months Ended
	Dec. 31, 2017
Brokers And Dealers [Abstract]
Deposits with Commodity Broker and Custodian	Note 5 - Deposits with Commodity Broker and Custodian The Fund defines cash as cash held by the Custodian. There were no cash equivalents held by the Fund as of December 31, 2017 and 2016. The Fund deposits cash and United States Treasury Obligations with the Commodity Broker, subject to CFTC regulations and various exchange and broker requirements. The combination of the Fund’s deposits with its Commodity Broker of cash and United States Treasury Obligations and the unrealized profit or loss on open futures contracts represents the Fund’s overall equity in its broker trading account. To meet the Fund’s maintenance margin requirements, the Fund holds United States Treasury Obligations with the Commodity Broker. The Fund transfers cash to the Commodity Broker to satisfy variation margin requirements. The Fund earns interest on any excess cash deposited with the Commodity Broker and incurs interest expense on any deficit balance with the Commodity Broker. The Fund may deposit T-Bill ETFs and money market mutual funds with the Commodity Broker as margin, to the extent permissible under CFTC rules. The brokerage agreement with the Commodity Broker provides for the net settlement of all financial instruments covered by the agreement in the event of default or termination of any one contract. The Managing Owner will utilize any excess cash held at the Commodity Broker to offset any realized losses incurred in the commodity futures contracts, if available. To the extent that any excess cash held at the Commodity Broker is not adequate to cover any realized losses, a portion of the United States Treasury Obligations and T-Bill ETFs, if any, on deposit with the Commodity Broker will be sold to make additional cash available. For financial reporting purposes, the Fund offsets financial assets and financial liabilities that are subject to legally enforceable netting arrangements. The Fund’s remaining cash, United States Treasury Obligations, T-Bill ETFs and money market mutual fund holdings are on deposit with the Custodian. The Fund is permitted to temporarily carry a negative or overdrawn balance in its account with the Custodian. Such balances, if any at period-end, are shown on the Statements of Financial Condition under the payable caption Due to custodian

Additional Valuation Informatio

Additional Valuation Information	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Additional Valuation Information	Note 6 - Additional Valuation Information U.S. GAAP defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, under current market conditions. U.S. GAAP establishes a hierarchy that prioritizes the inputs to valuation methods, giving the highest priority to readily available unadjusted quoted prices in an active market for identical assets (Level 1) and the lowest priority to significant unobservable inputs (Level 3), generally when market prices are not readily available or are unreliable. Based on the valuation inputs, the securities or other investments are tiered into one of three levels. Changes in valuation methods or market conditions may result in transfers in or out of an investment’s assigned level: Level 1: Prices are determined using quoted prices in an active market for identical assets. Level 2: Prices are determined using other significant observable inputs. Observable inputs are inputs that other market participants may use in pricing a security. These may include quoted prices for similar securities, interest rates, prepayment speeds, credit risk, yield curves, loss severities, default rates, discount rates, volatilities and others. Level 3: Prices are determined using significant unobservable inputs. In situations where quoted prices or observable inputs are unavailable (for example, when there is little or no market activity for an investment at the end of the period), unobservable inputs may be used. Unobservable inputs reflect the Fund’s own assumptions about the factors market participants would use in determining fair value of the securities or instruments and would be based on the best available information. The levels assigned to the securities valuations may not be an indication of the risk or liquidity associated with investing in those securities. Because of the inherent uncertainties of valuation, the values reflected in the financial statements may materially differ from the value received upon actual sale of those investments. The Fund's policy is to recognize transfers in and out of the valuation levels as of the end of the reporting period. During the years ended December 31, 2017 and 2016, there were no material transfers between valuation levels. The following is a summary of the tiered valuation input levels as of December 31, 2017: Level 1 Level 2 Level 3 Total Investments in Securities United States Treasury Obligations $ — $ 244,408,079 $ — $ 244,408,079 Exchange-Traded Fund 15,990,513 — — 15,990,513 Money Market Mutual Fund 23,103,724 — — 23,103,724 Total Investments in Securities 39,094,237 244,408,079 — 283,502,316 Other Investments - Assets (a) Commodity Futures Contracts 31,489,170 — — 31,489,170 Total Investments $ 70,583,407 $ 244,408,079 $ — $ 314,991,486 (a) Unrealized appreciation (depreciation). The following is a summary of the tiered valuation input levels as of December 31, 2016: Level 1 Level 2 Level 3 Total United States Treasury Obligations $ — $ 252,671,516 $ — $ 252,671,516 Money Market Mutual Fund 19,276,827 — — 19,276,827 19,276,827 252,671,516 — 271,948,343 Commodity Futures Contracts (a) 12,495,905 — — 12,495,905 Total Investments $ 31,772,732 $ 252,671,516 $ — $ 284,444,248 (a) Unrealized appreciation (depreciation).

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments	Note 7 – Derivative Instruments The Fair Value of Derivative Instruments is as follows: December 31, 2017 December 31, 2016 Risk Exposure/Derivative Type (a) Assets Liabilities Assets Liabilities Commodity risk Commodity Futures Contracts $ 31,489,170 $ — $ 13,170,636 $ (674,731 ) (a) Includes cumulative appreciation (depreciation) of commodity futures contracts. Only the current day’s variation margin receivable (payable) is reported in the December 31, 2017 and December 31, 2016 Statements of Financial Condition for non-LME commodity futures contracts. The following table presents derivative instruments that are either subject to an enforceable netting agreement or offset by collateral arrangements as of December 31, 2017, net by contract: Financial Derivative Assets Financial Derivative Liabilities Net value of Collateral (Received)/Pledged(a) Counterparty Futures Contracts Futures Contracts derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 31,489,170 $ — $ 31,489,170 $ — $ — $ 31,489,170 The following table presents derivative instruments that are either subject to an enforceable netting agreement or offset by collateral arrangements as of December 31, 2016, net by contract: Financial Derivative Assets Financial Derivative Liabilities Net value of Collateral (Received)/Pledged(a) Counterparty Futures Contracts Futures Contracts derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 13,170,636 $ (674,731 ) $ 12,495,905 $ — $ — $ 12,495,905 (a) As of December 31, 2017 and December 31, 2016, a portion of the Fund’s U.S. Treasury Obligations were required to be deposited as maintenance margin in support of the Fund’s futures positions. The Effect of Derivative Instruments on the Statements of Income and Expenses is as follows: For the Years Ended Location of Gain or (Loss) on Derivatives December 31, Risk Exposure/Derivative Type Recognized in Income 2017 2016 2015 Commodity risk Commodity Futures Contracts Net Realized Gain (Loss) $ 52,294,017 $ 10,296,432 $ (55,724,875 ) Net Change in Unrealized Gain (Loss) 18,993,265 26,387,124 (417,044 ) Total $ 71,287,282 $ 36,683,556 $ (56,141,919 ) The table below summarizes the average monthly notional value of futures contracts outstanding during the period: For the Years Ended December 31, 2017 2016 2015 Average Notional Value $ 303,299,280 $ 164,728,036 $ 178,820,623

Investments in Affiliates

Investments in Affiliates	12 Months Ended
	Dec. 31, 2017
Investments In And Advances To Affiliates Schedule Of Investments [Abstract]
Investments in Affiliates	Note 8 -- Investments in Affiliates The Fund's investment adviser also serves as the adviser for PowerShares Treasury Collateral Portfolio, and therefore, PowerShares Treasury Collateral Portfolio is considered to be affiliated with the Fund. The following is a summary of the transactions in, and earnings from, investments in affiliates (excluding affiliated money market funds) for the year ended December 31, 2017. Value 12/31/2016 Purchases at Cost Proceeds from Sales Change in Unrealized Appreciation (Depreciation) Realized Gain (Loss) Value 12/31/2017 Dividend Income PowerShares Treasury Collateral Portfolio $ — $ 16,006,371 $ — $ (15,858 ) $ — $ 15,990,513 $ 113,445

Share Purchases and Redemptions

Share Purchases and Redemptions	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Share Purchases and Redemptions	Note 9 - Share Purchases and Redemptions (a) Purchases On any business day, an Authorized Participant may place an order with the Administrator, which also serves as the Fund’s transfer agent (“Transfer Agent”) to create one or more Baskets. Each Basket consists of a block of 200,000 Shares. For purposes of processing both creation and redemption orders, a “business day” means any day other than a day when banks in New York City are required or permitted to be closed. Creation orders must be placed by 10:00 a.m., Eastern Time. The day on which the Transfer Agent receives a valid creation order is the creation order date. The day on which a creation order is settled is the creation order settlement date. Cash settlement occurs at the creation order settlement date. As provided below, the creation order settlement date may occur up to two business days after the creation order date. By placing a creation order, and prior to delivery of such Baskets, an Authorized Participant’s Depository Trust Company (“DTC”) account is charged the non-refundable transaction fee due for the creation order. Unless otherwise agreed to by the Managing Owner and the Authorized Participant as provided in the next sentence, Baskets are issued on the creation order settlement date as of 2:45 p.m., Eastern Time, on the business day immediately following the creation order date at the applicable NAV per Share as of the closing time of the NYSE Arca or the last to close of the exchanges on which its futures contracts are traded, whichever is later, on the creation order date, but only if the required payment has been timely received. Upon submission of a creation order, the Authorized Participant may request the Managing Owner to agree to a creation order settlement date up to two business days after the creation order date. (b) Redemptions On any business day, an Authorized Participant may place an order with the Transfer Agent to redeem one or more Baskets. Redemption orders must be placed by 10:00 a.m., Eastern Time. The day on which the Managing Owner receives a valid redemption order is the redemption order date. The day on which a redemption order is settled is the redemption order settlement date. Cash settlement occurs at the redemption order settlement date. As provided below, the redemption order settlement date may occur up to two business days after the redemption order date. The redemption procedures allow Authorized Participants to redeem Baskets. Individual Shareholders may not redeem directly from the Fund. Instead, individual Shareholders may only redeem Shares in integral multiples of 200,000 and only through an Authorized Participant. Unless otherwise agreed to by the Managing Owner and the Authorized Participant as provided in the next sentence, by placing a redemption order, an Authorized Participant agrees to deliver the Baskets to be redeemed through DTC’s book-entry system to the Fund not later than the redemption order settlement date as of 2:45 p.m., Eastern Time, on the business day immediately following the redemption order date. Upon submission of a redemption order, the Authorized Participant may request the Managing Owner to agree to a redemption order settlement date up to two business days after the redemption order date. By placing a redemption order, and prior to receipt of the redemption proceeds, an Authorized Participant’s DTC account is charged the non-refundable transaction fee due for the redemption order. The redemption proceeds from the Fund consist of the cash redemption amount. The cash redemption amount is equal to the NAV of the number of Basket(s) requested in the Authorized Participant’s redemption order as of the closing time of the NYSE Arca or the last to close of the exchanges on which the Fund’s futures contracts are traded, whichever is later, on the redemption order date. The Managing Owner will distribute the cash redemption amount at the redemption order settlement date as of 2:45 p.m., Eastern Time, on the redemption order settlement date through DTC to the account of the Authorized Participant as recorded on DTC’s book-entry system. The redemption proceeds due from the Fund are delivered to the Authorized Participant at 2:45 p.m., Eastern Time, on the redemption order settlement date if, by such time, the Fund’s DTC account has been credited with the Baskets to be redeemed. If the Fund’s DTC account has not been credited with all of the Baskets to be redeemed by such time, the redemption distribution is delivered to the extent of whole Baskets received. Any remainder of the redemption distribution is delivered on the next business day to the extent of remaining whole Baskets received if the Transfer Agent receives the fee applicable to the extension of the redemption distribution date which the Managing Owner may, from time-to-time, determine and the remaining Baskets to be redeemed are credited to the Fund’s DTC account by 2:45 p.m., Eastern Time, on such next business day. Any further outstanding amount of the redemption order will be cancelled. The Managing Owner is also authorized to deliver the redemption distribution notwithstanding that the Baskets to be redeemed are not credited to the Fund’s DTC account by 2:45 p.m., Eastern Time, on the redemption order settlement date if the Authorized Participant has collateralized its obligation to deliver the Baskets through DTC’s book-entry system on such terms as the Managing Owner may determine from time-to-time.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10 - Commitments and Contingencies The Managing Owner, either in its own capacity or in its capacity as the Managing Owner and on behalf of the Fund, has entered into various service agreements that contain a variety of representations, or provide indemnification provisions related to certain risks service providers undertake in performing services for the Fund. The Trust Agreement provides for the Fund to indemnify the Managing Owner and any affiliate of the Managing Owner that provides services to the Fund to the maximum extent permitted by applicable law, subject to certain exceptions for disqualifying conduct by the Managing Owner or such an affiliate. The Fund's maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Fund that have not yet occurred. Further, the Fund has not had prior claims or losses pursuant to these contracts. Accordingly, the Managing Owner expects the risk of loss to be remote.

Financial Highlights

Financial Highlights	12 Months Ended
	Dec. 31, 2017
Investment Company Financial Highlights [Abstract]
Financial Highlights	Note 11 - Financial Highlights The Fund is presenting the following NAV and financial highlights related to investment performance for a Share outstanding for the years ended December 31, 2017, 2016 and 2015. An individual investor’s return and ratios may vary based on the timing of capital transactions NAV per Share is the NAV of the Fund divided by the number of outstanding Shares at the date of each respective period presented. Years Ended December 31, 2017 2016 2015 Net Asset Value Net asset value per Share, beginning of period $ 14.95 $ 11.87 $ 15.99 Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts 4.45 3.16 (4.00 ) Net investment income (loss) (a) (0.01 ) (0.08 ) (0.12 ) Net income (loss) 4.44 3.08 (4.12 ) Net asset value per Share, end of period $ 19.39 $ 14.95 $ 11.87 Market value per Share, beginning of period (b) $ 14.91 $ 11.91 $ 15.91 Market value per Share, end of period (b) $ 19.43 $ 14.91 $ 11.91 Ratio to average Net Assets Net investment income (loss) (0.04 )% (0.59 )% (0.86 )% Expenses, after waivers 0.77 % 0.88 % 0.90 % Expenses, prior to waivers 0.78 % 0.88 % 0.90 % Total Return, at net asset value (c) 29.70 % 25.95 % (25.77 )% Total Return, at market value (c) 30.32 % 25.19 % (25.14 )% (a) Based on average shares outstanding. (b) The mean between the last bid and ask prices. (c) Total Return, at NAV is calculated assuming an initial investment made at the NAV at the beginning of the period, reinvestment of all dividends and distributions at NAV during the period, and redemption of Shares on the last day of the period. Total Return, at NAV includes adjustments in accordance with U.S. GAAP and as such, the NAV for financial reporting purposes and the returns based upon those NAVs may differ from the NAVs and returns for shareholder transactions. Total Return, at market value is calculated assuming an initial investment made at the market value at the beginning of the period, reinvestment of all dividends and distributions at market value during the period, and redemption of Shares at the market value on the last day of the period. Not annualized for periods less than one year, if applicable.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	A. The financial statements of the Fund have been prepared using accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain reclassifications have been made to prior years’ financial statements to conform to the current year presentation. The Fund has determined that it meets the definition of an investment company and has prepared the financial statements in conformity with U.S. GAAP for investment companies in conformity with accounting and reporting guidance of the Financial Accounting Standards Board Accounting Standards Codification Topic 946, Financial Services Investment Companies
Accounting Estimates	B. Accounting Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates by a significant amount. In addition, the Fund monitors for material events or transactions that may occur or become known after the period-end date and before the date the financial statements are released to print.
Investment Valuations	C. Investment Valuations Investments in open-end and closed-end registered investment companies that do not trade on an exchange are valued at the end-of-day net asset value (“NAV”) per share. Investments in open-end and closed-end registered investment companies that trade on an exchange are valued at the last sales price or official closing price as of the close of the customary trading session on the exchange where the security is principally traded. United States Treasury Obligations are fair valued using an evaluated quote provided by an independent pricing service. Evaluated quotes provided by the pricing service may be determined without exclusive reliance on quoted prices, and may reflect appropriate factors such as developments related to specific securities, yield, quality, type of issue, coupon rate, maturity, individual trading characteristics and other market data. All debt obligations involve some risk of default with respect to interest and/or principal payments. Futures contracts are valued at the final settlement price set by an exchange on which they are principally traded. When market closing prices are not available, the Managing Owner may value an asset of the Fund pursuant to policies the Managing Owner has adopted, which are consistent with normal industry standards.
Investment Transactions and Investment Income	D. Investment Transactions and Investment Income Investment transactions are accounted for on a trade date basis. Realized gains or losses from the sale or disposition of securities or derivatives are determined on a specific identification basis and recognized in the Statements of Income and Expenses in the period in which the contract is closed or the sale or disposition occurs, respectively. Interest income on United States Treasury Obligations is recognized on an accrual basis when earned. Premiums and discounts are amortized or accreted over the life of the United States Treasury Obligations. Dividend income (net of withholding tax, if any) is recorded on the ex-dividend date.
Profit and Loss Allocations and Distributions	E. Profit and Loss Allocations and Distributions Pursuant to the Trust Agreement, income and expenses are allocated pro rata pro rata No distributions were paid for the years ended December 31, 2017, 2016 and 2015.
Routine Operational, Administrative and Other Ordinary Expenses	F. Routine Operational, Administrative and Other Ordinary Expenses Upon assuming the role of Managing Owner on the Closing Date, the Managing Owner assumed all routine operational, administrative and other ordinary expenses of the Fund, including, but not limited to, computer services, the fees and expenses of the Trustee, legal and accounting fees and expenses, tax preparation expenses, filing fees and printing, mailing and duplication costs. Prior to that date, the Predecessor Managing Owner assumed all routine operational, administrative and other ordinary expenses of the Fund. The Fund does not reimburse the Managing Owner for the routine operational, administrative and other ordinary expenses of the Fund. Accordingly, such expenses are not reflected in the Statements of Income and Expenses of the Fund.
Non-Recurring Fees and Expenses	G. Non-Recurring Fees and Expenses The Fund pays all non-recurring and unusual fees and expenses, if any, of itself, as determined by the Managing Owner. Non-recurring and unusual fees and expenses include fees and expenses, such as legal claims and liabilities, litigation costs, indemnification expenses or other non-routine expenses. Non-recurring and unusual fees and expenses, by their nature, are unpredictable in terms of timing and amount. For the years ended December 31, 2017, 2016 and 2015, the Fund did not incur such expenses.
Brokerage Commissions and Fees	H. Brokerage Commissions and Fees The Fund incurs all brokerage commissions, including applicable exchange fees, National Futures Association (“NFA”) fees, give-up fees, pit brokerage fees and other transaction related fees and expenses charged in connection with trading activities by the Commodity Broker (as defined below). These costs are recorded as Brokerage Commissions and Fees in the Statements of Income and Expenses. The Commodity Broker’s brokerage commissions and trading fees are determined on a contract-by-contract basis. On average, total charges paid to the Commodity Broker, as applicable were less than $19.00, $19.00 and $19.00 per round-turn trade during the years ended December 31, 2017, 2016 and 2015, respectively.
Income Taxes	I. Income Taxes The Fund is classified as a partnership for U.S. federal income tax purposes. Accordingly, the Fund will generally not incur U.S. federal income taxes. No provision for federal, state, and local income taxes has been made in the accompanying financial statements, as investors are individually liable for income taxes, if any, on their allocable share of the Fund’s income, gain, loss, deductions and other items. The Managing Owner has reviewed all of the Fund’s open tax years and major jurisdictions and concluded that there is no tax liability resulting from unrecognized tax benefits relating to uncertain tax positions taken or expected to be taken in future tax returns. The Fund is also not aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. The major tax jurisdiction for the Fund and the earliest tax year subject to examination: United States, 2014.
Commodity Futures Contracts	J. Commodity Futures Contracts The Fund utilizes derivative instruments to achieve its investment objective. A commodity futures contract is an agreement between counterparties to purchase or sell a specified underlying commodity for a specified price, or to pay or receive a cash amount based on the value of an index or other reference instrument, at a future date. Initial margin deposits required upon entering into futures contracts are satisfied by the segregation of specific securities or cash as collateral with the Commodity Broker. During the period that the commodity futures contracts are open, changes in the value of the contracts are recognized as unrealized gains or losses by recalculating the value of the contracts on a daily basis. Subsequent or variation margin payments are received or made on non-LME commodity futures contracts depending upon whether unrealized gains or losses are incurred. These amounts are reflected as a receivable or payable on the Statements of Financial Condition. For LME contracts, subsequent or variation margin payments are not made and the value of the contracts is presented as net unrealized appreciation (depreciation) on the Statements of Financial Condition. When LME or non-LME contracts are closed or expire, the Fund recognizes a realized gain or loss equal to the difference between the proceeds from, or cost of, the closing transaction and the Fund’s basis in the contract. Realized gains (losses) and changes in unrealized appreciation (depreciation) on open positions are determined on a specific identification basis and recognized in the Statements of Income and Expenses in the period in which the contract is closed or the changes occur, respectively.
Receivable/(Payable) for LME Contracts	K. Receivable/(Payable) for LME Contracts The Fund trades aluminum, copper and zinc commodity futures contracts on the LME. For settlement of futures contracts traded on the LME, cash is not transferred until the settled futures contracts expire. As of December 31, 2017, the Fund had a payable to the Commodity Broker of $731,031, related to net realized losses on LME contracts, which have been closed out but for which the contract was not yet expired. As of December 31, 2016, the Fund had a payable to the Commodity Broker of $129,711, related to net realized losses on LME contracts which have been closed out but for which the contract has not yet expired.

Additional Valuation Informat21

Additional Valuation Information (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of the Tiered Valuation Input Levels	The following is a summary of the tiered valuation input levels as of December 31, 2017: Level 1 Level 2 Level 3 Total Investments in Securities United States Treasury Obligations $ — $ 244,408,079 $ — $ 244,408,079 Exchange-Traded Fund 15,990,513 — — 15,990,513 Money Market Mutual Fund 23,103,724 — — 23,103,724 Total Investments in Securities 39,094,237 244,408,079 — 283,502,316 Other Investments - Assets (a) Commodity Futures Contracts 31,489,170 — — 31,489,170 Total Investments $ 70,583,407 $ 244,408,079 $ — $ 314,991,486 (a) Unrealized appreciation (depreciation). The following is a summary of the tiered valuation input levels as of December 31, 2016: Level 1 Level 2 Level 3 Total United States Treasury Obligations $ — $ 252,671,516 $ — $ 252,671,516 Money Market Mutual Fund 19,276,827 — — 19,276,827 19,276,827 252,671,516 — 271,948,343 Commodity Futures Contracts (a) 12,495,905 — — 12,495,905 Total Investments $ 31,772,732 $ 252,671,516 $ — $ 284,444,248 (a) Unrealized appreciation (depreciation).

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments and Effect of Derivative Instruments on Statements of Income and Expenses	The Fair Value of Derivative Instruments is as follows: December 31, 2017 December 31, 2016 Risk Exposure/Derivative Type (a) Assets Liabilities Assets Liabilities Commodity risk Commodity Futures Contracts $ 31,489,170 $ — $ 13,170,636 $ (674,731 ) (a) Includes cumulative appreciation (depreciation) of commodity futures contracts. Only the current day’s variation margin receivable (payable) is reported in the December 31, 2017 and December 31, 2016 Statements of Financial Condition for non-LME commodity futures contracts. The Effect of Derivative Instruments on the Statements of Income and Expenses is as follows: For the Years Ended Location of Gain or (Loss) on Derivatives December 31, Risk Exposure/Derivative Type Recognized in Income 2017 2016 2015 Commodity risk Commodity Futures Contracts Net Realized Gain (Loss) $ 52,294,017 $ 10,296,432 $ (55,724,875 ) Net Change in Unrealized Gain (Loss) 18,993,265 26,387,124 (417,044 ) Total $ 71,287,282 $ 36,683,556 $ (56,141,919 )
Summary of Gross and Net Amounts of Offsetting Assets and Liabilities	The following table presents derivative instruments that are either subject to an enforceable netting agreement or offset by collateral arrangements as of December 31, 2017, net by contract: Financial Derivative Assets Financial Derivative Liabilities Net value of Collateral (Received)/Pledged(a) Counterparty Futures Contracts Futures Contracts derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 31,489,170 $ — $ 31,489,170 $ — $ — $ 31,489,170 The following table presents derivative instruments that are either subject to an enforceable netting agreement or offset by collateral arrangements as of December 31, 2016, net by contract: Financial Derivative Assets Financial Derivative Liabilities Net value of Collateral (Received)/Pledged(a) Counterparty Futures Contracts Futures Contracts derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 13,170,636 $ (674,731 ) $ 12,495,905 $ — $ — $ 12,495,905 (a) As of December 31, 2017 and December 31, 2016, a portion of the Fund’s U.S. Treasury Obligations were required to be deposited as maintenance margin in support of the Fund’s futures positions.
Summary of Average Monthly Notional Value of Future Contracts Outstanding	The table below summarizes the average monthly notional value of futures contracts outstanding during the period: For the Years Ended December 31, 2017 2016 2015 Average Notional Value $ 303,299,280 $ 164,728,036 $ 178,820,623

Investments in Affiliates (Tabl

Investments in Affiliates (Tables)	12 Months Ended
	Dec. 31, 2017
Investments In And Advances To Affiliates Schedule Of Investments [Abstract]
Summary of Transactions in, and Earnings from, Investments in Affiliates (Excluding Affiliated Money Market Funds)	The following is a summary of the transactions in, and earnings from, investments in affiliates (excluding affiliated money market funds) for the year ended December 31, 2017. Value 12/31/2016 Purchases at Cost Proceeds from Sales Change in Unrealized Appreciation (Depreciation) Realized Gain (Loss) Value 12/31/2017 Dividend Income PowerShares Treasury Collateral Portfolio $ — $ 16,006,371 $ — $ (15,858 ) $ — $ 15,990,513 $ 113,445

Financial Highlights (Tables)

Financial Highlights (Tables)	12 Months Ended
	Dec. 31, 2017
Investment Company Financial Highlights [Abstract]
Schedule of Net Asset Value Per Share	NAV per Share is the NAV of the Fund divided by the number of outstanding Shares at the date of each respective period presented. Years Ended December 31, 2017 2016 2015 Net Asset Value Net asset value per Share, beginning of period $ 14.95 $ 11.87 $ 15.99 Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts 4.45 3.16 (4.00 ) Net investment income (loss) (a) (0.01 ) (0.08 ) (0.12 ) Net income (loss) 4.44 3.08 (4.12 ) Net asset value per Share, end of period $ 19.39 $ 14.95 $ 11.87 Market value per Share, beginning of period (b) $ 14.91 $ 11.91 $ 15.91 Market value per Share, end of period (b) $ 19.43 $ 14.91 $ 11.91 Ratio to average Net Assets Net investment income (loss) (0.04 )% (0.59 )% (0.86 )% Expenses, after waivers 0.77 % 0.88 % 0.90 % Expenses, prior to waivers 0.78 % 0.88 % 0.90 % Total Return, at net asset value (c) 29.70 % 25.95 % (25.77 )% Total Return, at market value (c) 30.32 % 25.19 % (25.14 )% (a) Based on average shares outstanding. (b) The mean between the last bid and ask prices. (c) Total Return, at NAV is calculated assuming an initial investment made at the NAV at the beginning of the period, reinvestment of all dividends and distributions at NAV during the period, and redemption of Shares on the last day of the period. Total Return, at NAV includes adjustments in accordance with U.S. GAAP and as such, the NAV for financial reporting purposes and the returns based upon those NAVs may differ from the NAVs and returns for shareholder transactions. Total Return, at market value is calculated assuming an initial investment made at the market value at the beginning of the period, reinvestment of all dividends and distributions at market value during the period, and redemption of Shares at the market value on the last day of the period. Not annualized for periods less than one year, if applicable.

Organization - Additional Infor

Organization - Additional Information (Detail)	Feb. 23, 2015USD ($)shares	Dec. 31, 2017Basketshares	Dec. 31, 2016shares	Aug. 03, 2006Trust
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of series of trust | Trust				7
Partners' capital contribution | $	$ 1,000
General shares, shares issued	40	40	40
Purchase agreement transaction date		Feb. 23, 2015
Treasury obligation measurement maximum maturity period		12 months
Number of shares issued per basket		200,000
Minimum number of Baskets that can be purchased | Basket		1

Summary of Significant Accoun26

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Distributed earnings	$ 0	$ 0	$ 0
Average charges paid to broker per round-turn trade, maximum	19	19	$ 19
Payable for LME contracts	$ 731,031	$ 129,711

Service Providers and Related27

Service Providers and Related Party Agreements - Additional Information (Detail) - USD ($)	Feb. 26, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Management fee percentage per annum of daily NAV		0.75%
Managing owner waived fees		$ 42,832	$ 8,810	$ 0
Bank of New York Mellon [Member]
Related Party Transaction [Line Items]
Cash transferred to custodian	$ 31,802,760
United States Treasury Obligations transferred to custodian	155,996,427
Commodity Broker [Member]
Related Party Transaction [Line Items]
United States Treasury Obligations transferred to Commodity Broker	$ 51,994,800

Deposits with Commodity Broke28

Deposits with Commodity Broker and Custodian - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Brokers And Dealers [Abstract]
Cash equivalents held by fund	$ 0	$ 0

Additional Valuation Informat29

Additional Valuation Information - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	$ 244,408,079	$ 252,671,516
Exchange-Traded Fund	15,990,513
Money Market Mutual Fund	23,103,724	19,276,827
Total Investments in Securities	283,502,316	271,948,343
Commodity Futures Contracts	31,489,170	12,495,905
Total Investments	314,991,486	284,444,248
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchange-Traded Fund	15,990,513
Money Market Mutual Fund	23,103,724	19,276,827
Total Investments in Securities	39,094,237	19,276,827
Commodity Futures Contracts	31,489,170	12,495,905
Total Investments	70,583,407	31,772,732
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	244,408,079	252,671,516
Total Investments in Securities	244,408,079	252,671,516
Total Investments	$ 244,408,079	$ 252,671,516

Derivative Instruments - Fair V

Derivative Instruments - Fair Value of Derivative Instruments (Detail) - Commodity Futures Contract [Member] - Not Designated as Hedging Instrument [Member] - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Assets	$ 31,489,170	$ 13,170,636
Liabilities		$ (674,731)

Derivative Instruments - Summar

Derivative Instruments - Summary of Gross and Net Amounts of Offsetting Assets and Liabilities (Detail) - Commodity Futures Contract [Member] - Morgan Stanley & Co. LLC [Member] - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Offsetting Assets And Liabilities [Line Items]
Financial Derivative Assets	$ 31,489,170	$ 13,170,636
Financial Derivative Liabilities		(674,731)
Net value of derivatives, Assets	31,489,170	12,495,905
Financial Derivative Assets, Net amount	$ 31,489,170	$ 12,495,905

Derivative Instruments - Effect

Derivative Instruments - Effect of Derivative Instruments on Statements of Income and Expenses (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Futures contracts, realized gain (loss)	$ 52,294,017	$ 10,296,432	$ (55,724,875)
Futures contracts, unrealized gain (loss)	18,993,265	26,387,124	(417,044)
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	71,255,932	36,679,030	(56,130,471)
Commodity Futures Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Futures contracts, realized gain (loss)	52,294,017	10,296,432	(55,724,875)
Futures contracts, unrealized gain (loss)	18,993,265	26,387,124	(417,044)
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	$ 71,287,282	$ 36,683,556	$ (56,141,919)

Derivative Instruments - Summ33

Derivative Instruments - Summary of Average Monthly and Quarterly Notional Value of Future Contracts Outstanding (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted Average [Member] | Commodity Futures Contract [Member]
Derivative [Line Items]
Average Notional Value	$ 303,299,280	$ 164,728,036	$ 178,820,623

Investments in Affiliates - Sum

Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Excluding Affiliated Money Market Funds) (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments In And Advances To Affiliates [Line Items]
Beginning Value		$ 19,276,827
Change in Unrealized Appreciation (Depreciation)		(15,054)	$ (10,429)	$ 7,629
Ending Value		39,094,237	$ 19,276,827
Affiliated Investments [Member]
Investments In And Advances To Affiliates [Line Items]
Ending Value		39,094,237
Affiliated Investments [Member] | Exchange-Traded Fund - PowerShares Treasury Collateral Portfolio [Member]
Investments In And Advances To Affiliates [Line Items]
Purchases at Cost		16,006,371
Change in Unrealized Appreciation (Depreciation)		(15,858)
Ending Value	[1]	15,990,513
Dividend Income		$ 113,445
[1]	Affiliated company. The security and the Fund are affiliated by having the same investment adviser. See Note 8.

Share Purchases and Redemptio35

Share Purchases and Redemptions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017Basketshares
Equity [Abstract]
Minimum number of Baskets that can be purchased	1
Minimum number of Baskets that can be redeemed	1
Number of shares issued per basket | shares	200,000

Financial Highlights - Schedule

Financial Highlights - Schedule of Net Asset Value Per Share (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Asset Value
Net asset value per Share, beginning of period	$ 14.95	$ 11.87	$ 15.99
Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	4.45	3.16	(4)
Net investment income (loss)	(0.01)	(0.08)	(0.12)
Net income (loss)	4.44	3.08	(4.12)
Net asset value per Share, end of period	19.39	14.95	11.87
Market value per Share, beginning of period	14.91	11.91	15.91
Market value per Share, end of period	$ 19.43	$ 14.91	$ 11.91
Ratio to average Net Assets
Net investment income (loss)	(0.04%)	(0.59%)	(0.86%)
Expenses, after waivers	0.77%	0.88%	0.90%
Expenses, prior to waivers	0.78%	0.88%	0.90%
Total Return, at net asset value	29.70%	25.95%	(25.77%)
Total Return, at market value	30.32%	25.19%	(25.14%)