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	DBA
Entity Registrant Name	POWERSHARES DB AGRICULTURE FUND
Entity Central Index Key	1,383,082
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	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		35,200,000
Entity Public Float			$ 694,750,000

Statements of Financial Conditi

Statements of Financial Condition - USD ($)		Dec. 31, 2017	Dec. 31, 2016
Assets
United States Treasury Obligations, at value (cost $514,764,046 and $702,232,971, respectively)		$ 514,714,860	$ 702,215,941
Affiliated Investments, at value (cost $124,826,575 and $19,456,137, respectively)		124,748,306	19,456,137
Other investments:
Variation margin receivable- Commodity Futures Contracts		442,552
Cash held by custodian	[1]	2,260,923	2,181,236
Receivable for:
Dividends from affiliates		33,612	10,304
Total assets		642,200,253	723,863,618
Other investments:
Variation margin payable- Commodity Futures Contracts			114,786
Payable for:
Management fees		444,415	516,160
Brokerage commissions and fees		4,091	3,102
Total liabilities		448,506	634,048
Commitments and Contingencies (Note 10)
Equity
Shareholder's equity—General Shares		750	799
Shareholders' equity—Shares		641,750,997	723,228,771
Total shareholders' equity		641,751,747	723,229,570
Total liabilities and equity		$ 642,200,253	$ 723,863,618
General Shares outstanding		40	40
Shares outstanding		34,200,000	36,200,000
Net asset value per share		$ 18.76	$ 19.98
Market value per share		$ 18.75	$ 19.98
[1]	Cash at December 31, 2017, 2016 and 2015 reflects cash held by the Custodian

Statements of Financial Condit3

Statements of Financial Condition (Parenthetical) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Investments, cost	$ 639,590,621	$ 721,689,108
Affiliated Investments [Member]
Affiliated Investments, at Cost	124,826,575	19,456,137
US Treasury Bill Securities [Member]
Investments, cost	$ 514,764,046	$ 702,232,971

Schedule of Investments - Treas

Schedule of Investments - Treasury Bills and Affiliated Investments - USD ($)		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		99.64%		99.78%
Value		$ 514,714,860		$ 702,215,941
Affiliated Investments, at Value		124,748,306		19,456,137
Total Investments in Securities		639,463,166		721,672,078
Investments, cost		$ 639,590,621		721,689,108
Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		19.44%
Affiliated Investments, at Value		$ 124,748,306
Affiliated Investments, at Cost		$ 124,826,575		$ 19,456,137
U.S. Treasury Bills, 1.180% due January 4, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	23.37%
Value	[1]	$ 149,990,594
Principal Value	[1]	$ 150,000,000
Investment Interest Rate	[1]	1.18%
Investment Maturity Date	[1]	Jan. 4, 2018
U.S. Treasury Bills, 1.245% due January 18, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	4.98%
Value	[1]	$ 31,982,453
Principal Value	[1]	$ 32,000,000
Investment Interest Rate	[1]	1.245%
Investment Maturity Date	[1]	Jan. 18, 2018
U.S. Treasury Bills, 1.285% due February 22, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	7.47%
Value	[1]	$ 47,914,320
Principal Value	[1]	$ 48,000,000
Investment Interest Rate	[1]	1.285%
Investment Maturity Date	[1]	Feb. 22, 2018
U.S. Treasury Bills, 1.285% due March 1, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	23.17%
Value	[1],[2]	$ 148,695,730
Principal Value	[1],[2]	$ 149,000,000
Investment Interest Rate	[1],[2]	1.285%
Investment Maturity Date	[1],[2]	Mar. 1, 2018
Restricted for maintenance margin		$ 99,790,000
U.S. Treasury Bills, 1.450% due June 7, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	21.21%
Value	[1]	$ 136,131,763
Principal Value	[1]	$ 137,000,000
Investment Interest Rate	[1]	1.45%
Investment Maturity Date	[1]	Jun. 7, 2018
United States Treasury Obligations [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		80.20%	[1]	97.09%	[3]
Value		$ 514,714,860	[1]	$ 702,215,941	[3]
Investments, cost		$ 514,764,046		$ 702,232,971
Exchange-Traded Fund - PowerShares Treasury Collateral Portfolio [Member] | Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[4]	12.30%
Affiliated Investments, at Value	[4]	$ 78,920,919
Shares	[4]	749,700
Affiliated Investments, at Cost	[4]	$ 78,999,188
Money Market Mutual Fund - Invesco Premier U.S. Government Money Portfolio - Institutional Class [Member] | Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		7.14%	[5]	2.69%	[6]
Affiliated Investments, at Value		$ 45,827,387	[5]	$ 19,456,137	[6]
Shares		45,827,387	[5]	19,456,137	[6]
Investment Interest Rate		1.15%	[5]	0.41%	[6]
Affiliated Investments, at Cost		$ 45,827,387	[5]	$ 19,456,137	[6]
U.S. Treasury Bills, 0.490% due January 19, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3]			17.56%
Value	[3]			$ 126,977,013
Principal Value	[3]			$ 127,000,000
Investment Interest Rate	[3]			0.49%
Investment Maturity Date	[3]			Jan. 19, 2017
U.S. Treasury Bills, 0.485% due January 26, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3]			9.81%
Value	[3]			$ 70,981,327
Principal Value	[3]			$ 71,000,000
Investment Interest Rate	[3]			0.485%
Investment Maturity Date	[3]			Jan. 26, 2017
U.S. Treasury Bills, 0.490% due March 2, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3]			17.13%
Value	[3]			$ 123,905,140
Principal Value	[3]			$ 124,000,000
Investment Interest Rate	[3]			0.49%
Investment Maturity Date	[3]			Mar. 2, 2017
U.S. Treasury Bills, 0.530% due April 6, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3],[7]			32.03%
Value	[3],[7]			$ 231,687,264
Principal Value	[3],[7]			$ 232,000,000
Investment Interest Rate	[3],[7]			0.53%
Investment Maturity Date	[3],[7]			Apr. 6, 2017
Restricted for maintenance margin				$ 104,853,000
U.S. Treasury Bills, 0.625% due May 18, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3]			20.56%
Value	[3]			$ 148,665,197
Principal Value	[3]			$ 149,000,000
Investment Interest Rate	[3]			0.625%
Investment Maturity Date	[3]			May 18, 2017
[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 $99,790,000 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 $104,853,000 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		$ 639,463,166		$ 721,672,078
Long [Member] | Futures [Member]
Schedule of Investments [Line Items]
Value	[1]	(31,751,138)
Unrealized Appreciation (Depreciation)		$ (31,751,138)	[1]	$ (24,100,168)	[2]
Long [Member] | Futures [Member] | Corn [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		4,314		4,811
Expiration Date		Sep. 30, 2018		Sep. 30, 2017
Notional Value		$ 80,833,575		$ 89,304,188
Value	[1]	(6,550,383)
Unrealized Appreciation (Depreciation)		$ (6,550,383)	[1]	$ 934,349	[2]
Long [Member] | Futures [Member] | Soybean [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,646		1,857
Expiration Date		Nov. 30, 2018		Nov. 30, 2017
Notional Value		$ 80,304,225		$ 91,851,862
Value	[1]	(893,025)
Unrealized Appreciation (Depreciation)		$ (893,025)	[1]	$ 2,343,146	[2]
Long [Member] | Futures [Member] | Wheat [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,766		1,994
Expiration Date		Jul. 31, 2018		Jul. 31, 2017
Notional Value		$ 40,021,975		$ 43,294,725
Value	[1]	(5,174,053)
Unrealized Appreciation (Depreciation)		$ (5,174,053)	[1]	$ (10,374,494)	[2]
Long [Member] | Futures [Member] | Wheat KCB [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,749		2,012
Expiration Date		Jul. 31, 2018		Jul. 31, 2017
Notional Value		$ 40,073,962		$ 44,389,750
Value	[1]	(5,319,693)
Unrealized Appreciation (Depreciation)		$ (5,319,693)	[1]	$ (8,400,291)	[2]
Long [Member] | Futures [Member] | Feeder Cattle [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		357		529
Expiration Date		Mar. 31, 2018		Mar. 31, 2017
Notional Value		$ 25,467,488		$ 33,088,950
Value	[1]	(426,800)
Unrealized Appreciation (Depreciation)		$ (426,800)	[1]	$ 625,968	[2]
Long [Member] | Futures [Member] | Lean Hogs [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,982		2,825
Expiration Date		Feb. 28, 2018		Feb. 28, 2017
Notional Value		$ 56,903,220		$ 74,749,500
Value	[1]	32,068
Unrealized Appreciation (Depreciation)		$ 32,068	[1]	$ 13,494,886	[2]
Long [Member] | Futures [Member] | Live Cattle [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,613		2,219
Expiration Date		Feb. 28, 2018		Feb. 28, 2017
Notional Value		$ 78,424,060		$ 103,005,980
Value	[1]	(5,834,068)
Unrealized Appreciation (Depreciation)		$ (5,834,068)	[1]	$ 10,023,897	[2]
Long [Member] | Futures [Member] | Cocoa [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		3,370		3,329
Expiration Date		Mar. 31, 2018		Mar. 31, 2017
Notional Value		$ 63,760,400		$ 70,774,540
Value	[1]	(7,642,315)
Unrealized Appreciation (Depreciation)		$ (7,642,315)	[1]	$ (12,524,796)	[2]
Long [Member] | Futures [Member] | Coffee [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		1,522		1,279
Expiration Date		Mar. 31, 2018		Mar. 31, 2017
Notional Value		$ 72,028,650		$ 65,732,606
Value	[1]	(1,419,248)
Unrealized Appreciation (Depreciation)		$ (1,419,248)	[1]	$ (16,548,729)	[2]
Long [Member] | Futures [Member] | Cotton [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		536		591
Expiration Date		Mar. 31, 2018		Mar. 31, 2017
Notional Value		$ 21,072,840		$ 20,877,075
Value	[1]	2,588,909
Unrealized Appreciation (Depreciation)		$ 2,588,909	[1]	$ 471,475	[2]
Long [Member] | Futures [Member] | Sugar [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract		4,864		4,126
Expiration Date		Oct. 31, 2018		Sep. 30, 2017
Notional Value		$ 82,859,213		$ 86,183,888
Value	[1]	(1,112,530)
Unrealized Appreciation (Depreciation)		$ (1,112,530)	[1]	$ (4,145,579)	[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 Expense - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Interest Income	$ 5,059,883	$ 2,074,961	$ 213,932
Dividends from Affiliates	837,230	44,644
Total Income	5,897,113	2,119,605	213,932
Expenses
Management Fee	6,129,228	6,370,834	7,307,551
Brokerage Commissions and Fees	582,683	553,138	676,093
Interest Expense	6,652	13,261	11,025
Total Expenses	6,718,563	6,937,233	7,994,669
Less: Waivers	(141,040)	(24,645)	0
Net Expenses	6,577,523	6,912,588	7,994,669
Net Investment Income (Loss)	(680,410)	(4,792,983)	(7,780,737)
Net Realized Gain (Loss) on
United States Treasury Obligations	(5,173)	(1,951)	(236)
Commodity Futures Contracts	(37,799,803)	(2,817,129)	(215,438,348)
Net Realized Gain (Loss)	(37,804,976)	(2,819,080)	(215,438,584)
Net Change in Unrealized Gain (Loss) on
United States Treasury Obligations	(32,156)	(37,137)	14,311
Affiliated Investments	(78,269)
Commodity Futures Contracts	(7,650,970)	(23,242,989)	55,135,021
Net Change in Unrealized Gain (Loss)	(7,761,395)	(23,280,126)	55,149,332
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(45,566,371)	(26,099,206)	(160,289,252)
Net Income (Loss)	$ (46,246,781)	$ (30,892,189)	$ (168,069,989)

Statement of Changes in Shareho

Statement of Changes in Shareholders' Equity - USD ($)	Total	General Shares [Member]	Shares [Member]
Balance - Value at Dec. 31, 2014	$ 1,037,947,709	$ 993	$ 1,037,946,716
Balance - Shares at Dec. 31, 2014		40	41,800,000
Purchases of Shares - Value	139,873,537		$ 139,873,537
Purchases of Shares - Shares			6,200,000
Redemption of Shares - Value	(335,872,630)		$ (335,872,630)
Redemption of Shares - Shares			(15,400,000)
Net Increase (Decrease) due to Share Transactions, value	(195,999,093)		$ (195,999,093)
Net Increase (Decrease) due to Share Transactions, shares			(9,200,000)
Net Income (Loss)
Net Investment Income (Loss)	(7,780,737)	$ (8)	$ (7,780,729)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(215,438,584)	(213)	(215,438,371)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	55,149,332	55	55,149,277
Net Income (Loss)	(168,069,989)	(166)	(168,069,823)
Net Change in Shareholders' Equity, value	(364,069,082)	(166)	$ (364,068,916)
Net Change in Shareholders' Equity, shares			(9,200,000)
Balance - Value at Dec. 31, 2015	673,878,627	$ 827	$ 673,877,800
Balance - Shares at Dec. 31, 2015		40	32,600,000
Purchases of Shares - Value	315,204,237		$ 315,204,237
Purchases of Shares - Shares			15,000,000
Redemption of Shares - Value	(234,961,105)		$ (234,961,105)
Redemption of Shares - Shares			(11,400,000)
Net Increase (Decrease) due to Share Transactions, value	80,243,132		$ 80,243,132
Net Increase (Decrease) due to Share Transactions, shares			3,600,000
Net Income (Loss)
Net Investment Income (Loss)	(4,792,983)	$ (4)	$ (4,792,979)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(2,819,080)	(3)	(2,819,077)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(23,280,126)	(21)	(23,280,105)
Net Income (Loss)	(30,892,189)	(28)	(30,892,161)
Net Change in Shareholders' Equity, value	49,350,943	(28)	$ 49,350,971
Net Change in Shareholders' Equity, shares			3,600,000
Balance - Value at Dec. 31, 2016	723,229,570	$ 799	$ 723,228,771
Balance - Shares at Dec. 31, 2016		40	36,200,000
Purchases of Shares - Value	231,714,535		$ 231,714,535
Purchases of Shares - Shares			11,600,000
Redemption of Shares - Value	(266,945,577)		$ (266,945,577)
Redemption of Shares - Shares			(13,600,000)
Net Increase (Decrease) due to Share Transactions, value	(35,231,042)		$ (35,231,042)
Net Increase (Decrease) due to Share Transactions, shares			(2,000,000)
Net Income (Loss)
Net Investment Income (Loss)	(680,410)	$ (1)	$ (680,409)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(37,804,976)	(40)	(37,804,936)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(7,761,395)	(8)	(7,761,387)
Net Income (Loss)	(46,246,781)	(49)	(46,246,732)
Net Change in Shareholders' Equity, value	(81,477,823)	(49)	$ (81,477,774)
Net Change in Shareholders' Equity, shares			(2,000,000)
Balance - Value at Dec. 31, 2017	$ 641,751,747	$ 750	$ 641,750,997
Balance - Shares at Dec. 31, 2017		40	34,200,000

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)		$ (46,246,781)		$ (30,892,189)		$ (168,069,989)
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Cost of securities purchased		(2,049,375,350)		(2,811,201,297)		(3,274,025,322)
Proceeds from securities sold and matured		2,241,898,985		2,737,973,365		3,696,283,942
Cost of affiliated investments purchased		(1,337,361,959)		(297,350,547)
Proceeds from affiliated investments sold		1,231,991,521		277,894,410
Net accretion of discount on United States Treasury Obligations		(5,059,883)		(2,074,961)		(213,932)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments		5,173		1,951		236
Net change in unrealized (gain) loss on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts		110,425		37,137		(55,149,332)
Cash transfer to Commodity Broker to satisfy variation margin requirements (Note 4)						(88,823,232)
Cash received (paid) to Commodity Broker to satisfy open variation margin, net (Note 4)						87,966,053
Change in operating assets and liabilities:
Variation margin- Commodity Futures Contracts		(557,338)		2,273,022		(2,158,236)
Dividends from affiliates		(23,308)		(10,304)
Management fees		(71,745)		(19,958)		(274,688)
Brokerage commissions and fees		989		(1,897)		732
Net cash provided by (used for) operating activities		35,310,729		(123,371,268)		195,536,232
Cash flows from financing activities:
Proceeds from purchases of Shares		231,714,535		315,204,237		139,873,537
Redemption of Shares		(266,945,577)		(234,961,105)		(340,838,884)
Net cash provided by (used for) financing activities		(35,231,042)		80,243,132		(200,965,347)
Net change in cash		79,687		(43,128,136)		(5,429,115)
Cash at beginning of period		2,181,236	[1]	45,309,372	[1]	50,738,487	[2]
Cash at end of period	[1]	2,260,923		2,181,236		45,309,372
Supplemental disclosure of cash flow information
Cash paid for interest		$ 6,652		$ 13,261		$ 11,025
[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 Agriculture Fund (the “Fund”), a separate series of PowerShares DB Multi-Sector Commodity Trust (the “Trust”), 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 Diversified Agriculture 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 commodities comprising the Index are Corn, Soybeans, Wheat, Kansas City Wheat, Sugar, Cocoa, Coffee, Cotton, Live Cattle, Feeder Cattle and Lean Hogs (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 $7.00, $7.00 and $7.00 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 depending upon whether unrealized gains or losses are incurred. These amounts are reflected as a receivable or payable on the Statements of Financial Condition. When the 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.

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 0.85% 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 $141,040 and $24,645 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 $50,738,487 of cash and $1,239,965,626 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, $164,983,500 of United States Treasury Obligations from the Custodian to the Commodity Broker to satisfy variation margin requirements and $88,823,232 of cash from the Custodian to the Commodity Broker to satisfy variation margin requirements for open commodity futures contracts. Effective February 26, 2015, the Managing Owner began transferring cash daily from the Custodian to the Commodity Broker to satisfy the previous day’s variation margin on open futures contracts. 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 $ — $ 514,714,860 $ — $ 514,714,860 Exchange-Traded Fund 78,920,919 — — 78,920,919 Money Market Mutual Fund 45,827,387 — — 45,827,387 Total Investments in Securities 124,748,306 514,714,860 — 639,463,166 Other Investments - Assets (a) Commodity Futures Contracts 2,620,977 — — 2,620,977 Other Investments - Liabilities (a) Commodity Futures Contracts (34,372,115 ) — — (34,372,115 ) Total Other Investments (31,751,138 ) — — (31,751,138 ) Total Investments $ 92,997,168 $ 514,714,860 $ — $ 607,712,028 (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 $ — $ 702,215,941 $ — $ 702,215,941 Money Market Mutual Fund 19,456,137 — — 19,456,137 19,456,137 702,215,941 — 721,672,078 Commodity Futures Contracts (a) (24,100,168 ) — — (24,100,168 ) Total Investments $ (4,644,031 ) $ 702,215,941 $ — $ 697,571,910 (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 $ 2,620,977 $ (34,372,115 ) $ 27,893,721 $ (51,993,889 ) (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. 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 Collateral (Received)/Pledged (a) Counterparty Futures Contracts Futures Contracts Net value of derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 34,814,667 $ (34,372,115 ) $ 442,552 $ — $ — $ 442,552 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 Collateral (Received)/Pledged (a) Counterparty Futures Contracts Futures Contracts Net value of derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 51,879,103 $ (51,993,889 ) $ (114,786 ) $ 114,786 $ — $ — (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: Location of Gain or (Loss) on Derivatives Years Ended December 31, Risk Exposure/Derivative Type Recognized in Income 2017 2016 2015 Commodity risk Commodity Futures Contracts Net Realized Gain (Loss) $ (37,799,803 ) $ (2,817,129 ) $ (215,438,348 ) Net Change in Unrealized Gain (Loss) (7,650,970 ) (23,242,989 ) 55,135,021 Total $ (45,450,773 ) $ (26,060,118 ) $ (160,303,327 ) The table below summarizes the average monthly notional value of futures contracts outstanding during the period: Years Ended December 31, 2017 2016 2015 Average Notional Value $ 718,980,615 $ 744,214,472 $ 859,262,920

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 $ — $ 78,999,188 $ — $ (78,269 ) $ — $ 78,920,919 $ 559,906

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 $ 19.98 $ 20.67 $ 24.83 Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts (1.20 ) (0.56 ) (3.96 ) Net investment income (loss) (a) (0.02 ) (0.13 ) (0.20 ) Net income (loss) (1.22 ) (0.69 ) (4.16 ) Net asset value per Share, end of period $ 18.76 $ 19.98 $ 20.67 Market value per Share, beginning of period (b) $ 19.98 $ 20.62 $ 24.90 Market value per Share, end of period (b) $ 18.75 $ 19.98 $ 20.62 Ratio to average Net Assets Net investment income (loss) (0.09 )% (0.64 )% (0.91 )% Expenses, after waivers 0.91 % 0.92 % 0.93 % Expenses, prior to waivers 0.93 % 0.93 % 0.93 % Total Return, at net asset value (c) (6.11 )% (3.34 )% (16.75 )% Total Return, at market value (c) (6.16 )% (3.10 )% (17.19 )% (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 $7.00, $7.00 and $7.00 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 depending upon whether unrealized gains or losses are incurred. These amounts are reflected as a receivable or payable on the Statements of Financial Condition. When the 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.

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 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 $ — $ 514,714,860 $ — $ 514,714,860 Exchange-Traded Fund 78,920,919 — — 78,920,919 Money Market Mutual Fund 45,827,387 — — 45,827,387 Total Investments in Securities 124,748,306 514,714,860 — 639,463,166 Other Investments - Assets (a) Commodity Futures Contracts 2,620,977 — — 2,620,977 Other Investments - Liabilities (a) Commodity Futures Contracts (34,372,115 ) — — (34,372,115 ) Total Other Investments (31,751,138 ) — — (31,751,138 ) Total Investments $ 92,997,168 $ 514,714,860 $ — $ 607,712,028 (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 $ — $ 702,215,941 $ — $ 702,215,941 Money Market Mutual Fund 19,456,137 — — 19,456,137 19,456,137 702,215,941 — 721,672,078 Commodity Futures Contracts (a) (24,100,168 ) — — (24,100,168 ) Total Investments $ (4,644,031 ) $ 702,215,941 $ — $ 697,571,910 (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 $ 2,620,977 $ (34,372,115 ) $ 27,893,721 $ (51,993,889 ) (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. The Effect of Derivative Instruments on the Statements of Income and Expenses is as follows: Location of Gain or (Loss) on Derivatives Years Ended December 31, Risk Exposure/Derivative Type Recognized in Income 2017 2016 2015 Commodity risk Commodity Futures Contracts Net Realized Gain (Loss) $ (37,799,803 ) $ (2,817,129 ) $ (215,438,348 ) Net Change in Unrealized Gain (Loss) (7,650,970 ) (23,242,989 ) 55,135,021 Total $ (45,450,773 ) $ (26,060,118 ) $ (160,303,327 )
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 Collateral (Received)/Pledged (a) Counterparty Futures Contracts Futures Contracts Net value of derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 34,814,667 $ (34,372,115 ) $ 442,552 $ — $ — $ 442,552 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 Collateral (Received)/Pledged (a) Counterparty Futures Contracts Futures Contracts Net value of derivatives Non-Cash Cash Net amount Morgan Stanley & Co. LLC $ 51,879,103 $ (51,993,889 ) $ (114,786 ) $ 114,786 $ — $ — (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: Years Ended December 31, 2017 2016 2015 Average Notional Value $ 718,980,615 $ 744,214,472 $ 859,262,920

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 $ — $ 78,999,188 $ — $ (78,269 ) $ — $ 78,920,919 $ 559,906

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 $ 19.98 $ 20.67 $ 24.83 Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts (1.20 ) (0.56 ) (3.96 ) Net investment income (loss) (a) (0.02 ) (0.13 ) (0.20 ) Net income (loss) (1.22 ) (0.69 ) (4.16 ) Net asset value per Share, end of period $ 18.76 $ 19.98 $ 20.67 Market value per Share, beginning of period (b) $ 19.98 $ 20.62 $ 24.90 Market value per Share, end of period (b) $ 18.75 $ 19.98 $ 20.62 Ratio to average Net Assets Net investment income (loss) (0.09 )% (0.64 )% (0.91 )% Expenses, after waivers 0.91 % 0.92 % 0.93 % Expenses, prior to waivers 0.93 % 0.93 % 0.93 % Total Return, at net asset value (c) (6.11 )% (3.34 )% (16.75 )% Total Return, at market value (c) (6.16 )% (3.10 )% (17.19 )% (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	May 23, 2005Trust
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of series of trusts | Trust				7
Purchase agreement transaction date		Feb. 23, 2015
Partners' capital contribution | $	$ 1,000
General shares, shares issued	40	40	40
Treasury obligation measurement maximum maturity period		12 months
Minimum number of Baskets that can be purchased | Basket		1
Number of shares issued per basket		200,000

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	$ 7	$ 7	$ 7

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		0.85%
Managing owner waived fees		$ 141,040	$ 24,645	$ 0
Cash transfer to Commodity Broker to satisfy variation margin requirements				$ (88,823,232)
Bank of New York Mellon [Member]
Related Party Transaction [Line Items]
Cash transferred to custodian	$ 50,738,487
United States Treasury Obligations transferred to custodian	1,239,965,626
Commodity Broker [Member]
Related Party Transaction [Line Items]
United States Treasury Obligations transferred to Commodity Broker	164,983,500
Cash transfer to Commodity Broker to satisfy variation margin requirements	$ 88,823,232

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	$ 514,714,860	$ 702,215,941
Exchange-Traded Fund	78,920,919
Money Market Mutual Fund	45,827,387	19,456,137
Total Investments in Securities	639,463,166	721,672,078
Commodity Futures Contracts, Appreciation	2,620,977
Commodity Futures Contracts, Depreciation	(34,372,115)
Commodity Futures Contracts	(31,751,138)	(24,100,168)
Total Investments	607,712,028	697,571,910
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchange-Traded Fund	78,920,919
Money Market Mutual Fund	45,827,387	19,456,137
Total Investments in Securities	124,748,306	19,456,137
Commodity Futures Contracts, Appreciation	2,620,977
Commodity Futures Contracts, Depreciation	(34,372,115)
Commodity Futures Contracts	(31,751,138)	(24,100,168)
Total Investments	92,997,168	(4,644,031)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	514,714,860	702,215,941
Total Investments in Securities	514,714,860	702,215,941
Total Investments	$ 514,714,860	$ 702,215,941

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	$ 2,620,977	$ 27,893,721
Liabilities	$ (34,372,115)	$ (51,993,889)

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, Futures Contracts	$ 34,814,667	$ 51,879,103
Financial Derivative Liabilities, Futures Contracts	(34,372,115)	(51,993,889)
Net value of derivatives, Assets	442,552
Financial Derivative Assets, Net amount	$ 442,552
Net value of derivatives, Liabilities		(114,786)
Collateral (Received)/Pledged, Non-Cash		$ 114,786

Derivative Instruments - Fair32

Derivative Instruments - Fair Value of Derivative Instruments and 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)	$ (37,799,803)	$ (2,817,129)	$ (215,438,348)
Futures contracts, unrealized gain (loss)	(7,650,970)	(23,242,989)	55,135,021
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(45,566,371)	(26,099,206)	(160,289,252)
Commodity Futures Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Futures contracts, realized gain (loss)	(37,799,803)	(2,817,129)	(215,438,348)
Futures contracts, unrealized gain (loss)	(7,650,970)	(23,242,989)	55,135,021
Net Realized and Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	$ (45,450,773)	$ (26,060,118)	$ (160,303,327)

Derivative Instruments - Summ33

Derivative Instruments - Summary of Average Monthly 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	$ 718,980,615	$ 744,214,472	$ 859,262,920

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		$ 19,456,137
Change in Unrealized Appreciation (Depreciation)		(32,156)	$ (37,137)	$ 14,311
Ending Value		124,748,306	$ 19,456,137
Affiliated Investments [Member]
Investments in and Advances to Affiliates [Line Items]
Ending Value		124,748,306
Affiliated Investments [Member] | Exchange-Traded Fund - PowerShares Treasury Collateral Portfolio [Member]
Investments in and Advances to Affiliates [Line Items]
Purchases at Cost		78,999,188
Change in Unrealized Appreciation (Depreciation)		(78,269)
Ending Value	[1]	78,920,919
Dividend Income		$ 559,906
[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	$ 19.98	$ 20.67	$ 24.83
Net realized and change in unrealized gain (loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(1.20)	(0.56)	(3.96)
Net investment income (loss)	(0.02)	(0.13)	(0.20)
Net income (loss)	(1.22)	(0.69)	(4.16)
Net asset value per Share, end of period	18.76	19.98	20.67
Market value per Share, beginning of period	19.98	20.62	24.90
Market value per Share, end of period	$ 18.75	$ 19.98	$ 20.62
Ratio to average Net Assets
Net investment income (loss)	(0.09%)	(0.64%)	(0.91%)
Expenses, after waivers	0.91%	0.92%	0.93%
Expenses, prior to waivers	0.93%	0.93%	0.93%
Total Return, at net asset value	(6.11%)	(3.34%)	(16.75%)
Total Return, at market value	(6.16%)	(3.10%)	(17.19%)