v2.4.0.8

Investments - Offsetting of Financial Assets and Liabilities (Detail) (USD $) | Mar. 31, 2014 | Dec. 31, 2013
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ProShares UltraShort DJ-UBS Commodity [Member] | Swap Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | $ 102,269 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 102,269 |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  | 27,665
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 27,665
ProShares UltraShort DJ-UBS Crude Oil [Member] | Swap Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 71,219 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 71,219 |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 764,150 | 2,332,900
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 764,150 | 2,332,900
ProShares UltraShort DJ-UBS Crude Oil [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 345,825 | 1,503,943
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 345,825 | 1,503,943
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares UltraShort DJ-UBS Natural Gas [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 2,752,495 | 1,520,548
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 2,752,495 | 1,520,548
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares UltraShort Gold [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 2,100 | 300
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 2,100 | 300
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares UltraShort Gold [Member] | Forward Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 8,531,762 | 5,633,053
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 8,531,762 | 5,633,053
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares UltraShort Silver [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 2,450
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 2,450
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 440 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 440 |
ProShares UltraShort Silver [Member] | Forward Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 7,742,580 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 7,742,580 |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  | 2,227,857
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 2,227,857
ProShares Short Euro [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 9,100
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 9,100
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 12,300 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 12,300 |
ProShares UltraShort Australian Dollar [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 89,099 | 86,166
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 89,099 | 86,166
ProShares UltraShort Euro [Member] | Foreign Currency Forward Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 151,351
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 151,351
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 3,724,310 | 13,899,858
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 3,724,310 | 13,899,858
ProShares UltraShort Yen [Member] | Foreign Currency Forward Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 6,121,534 | 31,317,568
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 6,121,534 | 31,317,568
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 1,275,150 | 1,930,884
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 1,275,150 | 1,930,884
ProShares Ultra DJ-UBS Commodity [Member] | Swap Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 15,078
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 15,078
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 114,128 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 114,128 |
ProShares Ultra DJ-UBS Crude Oil [Member] | Swap Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 959,951 | 1,957,893
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 959,951 | 1,957,893
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares Ultra DJ-UBS Crude Oil [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 121,862 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 121,862 |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  | 997,210
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 997,210
ProShares Ultra DJ-UBS Natural Gas [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 1,050,517 | 5,628,532
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 1,050,517 | 5,628,532
ProShares Ultra Gold [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 2,200 | 300
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 2,200 | 300
ProShares Ultra Gold [Member] | Forward Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 12,010,072 | 6,812,974
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 12,010,072 | 6,812,974
ProShares Ultra Silver [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 380 | 2,450
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 380 | 2,450
ProShares Ultra Silver [Member] | Forward Agreements [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 58,138,361 | 2,492,880
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 58,138,361 | 2,492,880
ProShares Ultra Australian Dollar [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 13,503 | 10,650
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 13,503 | 10,650
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
ProShares Ultra Euro [Member] | Foreign Currency Forward Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 21,019 | 120,908
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 21,019 | 120,908
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 35 | 19,946
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 35 | 19,946
ProShares Ultra Yen [Member] | Foreign Currency Forward Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 1,004 | 4,052
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 1,004 | 4,052
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 42,233 | 163,361
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 42,233 | 163,361
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 3,179,017
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 3,179,017
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 3,088,786 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 3,088,786 |
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  | 100,734
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  | 100,734
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 1,009,664 |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 1,009,664 |
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions | 24,525,510 | 3,356,803
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 24,525,510 | 3,356,803
ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Derivative [Line Items] |  |
Gross Amounts of Recognized Assets presented in the Statement of Financial Conditions | 6,484,331 | 603,833
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount | 6,484,331 | 603,833
Gross Amounts of Recognized Liabilities presented in the Statement of Financial Conditions |  |
Gross Amounts Offset in the Statement of Financial Conditions |  |
Net Amount |  |

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=20225523&loc=SL20225862-175312 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226008-175313 + Details
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