v3.10.0.1

Schedule of Investments - Forward Agreements (Detail) | 6 Months Ended
--- | ---
Jun. 30, 2018 USD ($)
ProShares Ultra Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation)/Value | $ (7,152,896) | [1]
ProShares Ultra Gold [Member] | Forward agreements with Citibank N.A. based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.55% | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ 47,200 | [1]
Notional Amount at Value | 59,059,000 | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ (2,546,835) | [1]
ProShares Ultra Gold [Member] | Forward agreements with Goldman Sachs International based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.67% | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ 37,420 | [1]
Notional Amount at Value | 46,820,652 | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ (1,977,494) | [1]
ProShares Ultra Gold [Member] | Forward agreements with Societe Generale based on 0.995 Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.67% | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ 13,000 | [1]
Notional Amount at Value | 16,265,860 | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ (676,179) | [1]
ProShares Ultra Gold [Member] | Forward agreements with UBS AG based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.53% | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ 33,400 | [1]
Notional Amount at Value | 41,789,746 | [1],[3]
Unrealized Appreciation (Depreciation)/Value | (1,952,388) | [1]
ProShares Ultra Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation)/Value | $ (14,148,711) | [4]
ProShares Ultra Silver [Member] | Forward agreements with Citibank N.A. based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.65% | [2],[4]
Settlement Date | Jul. 06, 2018 | [4]
Commitment to (Deliver)/Receive | $ 8,802,000 | [4]
Notional Amount at Value | 141,190,241 | [3],[4]
Unrealized Appreciation (Depreciation)/Value | $ (4,560,857) | [4]
ProShares Ultra Silver [Member] | Forward agreements with Goldman Sachs International based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.85% | [2],[4]
Settlement Date | Jul. 06, 2018 | [4]
Commitment to (Deliver)/Receive | $ 7,030,800 | [4]
Notional Amount at Value | 112,778,954 | [3],[4]
Unrealized Appreciation (Depreciation)/Value | $ (4,075,705) | [4]
ProShares Ultra Silver [Member] | Forward agreements with Societe Generale based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.83% | [2],[4]
Settlement Date | Jul. 06, 2018 | [4]
Commitment to (Deliver)/Receive | $ 3,284,000 | [4]
Notional Amount at Value | 52,677,330 | [3],[4]
Unrealized Appreciation (Depreciation)/Value | $ (1,789,967) | [4]
ProShares Ultra Silver [Member] | Forward agreements with UBS AG based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | 2.85% | [2],[4]
Settlement Date | Jul. 06, 2018 | [4]
Commitment to (Deliver)/Receive | $ 6,865,000 | [4]
Notional Amount at Value | 110,119,406 | [3],[4]
Unrealized Appreciation (Depreciation)/Value | (3,722,182) | [4]
ProShares UltraShort Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation)/Value | $ 2,276,610 | [1]
ProShares UltraShort Gold [Member] | Forward agreements with Citibank N.A. based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (2.05%) | [1],[5]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (14,300) | [1]
Notional Amount at Value | (17,892,875) | [1],[6]
Unrealized Appreciation (Depreciation)/Value | $ 802,900 | [1]
ProShares UltraShort Gold [Member] | Forward agreements with Goldman Sachs International based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (1.82%) | [1],[5]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (12,498) | [1]
Notional Amount at Value | (15,637,748) | [1],[6]
Unrealized Appreciation (Depreciation)/Value | $ 615,251 | [1]
ProShares UltraShort Gold [Member] | Forward agreements with Societe Generale based on 0.995 Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (1.77%) | [1],[5]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (4,800) | [1]
Notional Amount at Value | (6,005,856) | [1],[6]
Unrealized Appreciation (Depreciation)/Value | $ 246,078 | [1]
ProShares UltraShort Gold [Member] | Forward agreements with UBS AG based on 0.995 Fine Troy Ounce Gold [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (1.73%) | [1],[5]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (10,150) | [1]
Notional Amount at Value | (12,699,579) | [1],[6]
Unrealized Appreciation (Depreciation)/Value | 612,381 | [1]
ProShares UltraShort Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation)/Value | $ 1,452,785 | [1]
ProShares UltraShort Silver [Member] | Forward agreements with Citibank N.A. based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (2.15%) | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (1,093,000) | [1]
Notional Amount at Value | (17,532,485) | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ 582,164 | [1]
ProShares UltraShort Silver [Member] | Forward agreements with Goldman Sachs International based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (2.00%) | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (851,500) | [1]
Notional Amount at Value | (13,658,656) | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ 402,097 | [1]
ProShares UltraShort Silver [Member] | Forward agreements with Societe Generale based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (1.93%) | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (156,000) | [1]
Notional Amount at Value | (2,502,334) | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ 83,545 | [1]
ProShares UltraShort Silver [Member] | Forward agreements with UBS AG based on 0.999 Fine Troy Ounce Silver [Member] |  |
Schedule of Investments [Line Items] |  |
Rate Paid (Received) | (1.95%) | [1],[2]
Settlement Date | Jul. 06, 2018 | [1]
Commitment to (Deliver)/Receive | $ (781,000) | [1]
Notional Amount at Value | (12,527,787) | [1],[3]
Unrealized Appreciation (Depreciation)/Value | $ 384,979 | [1]
[1] | The positions and counterparties herein are as of June 30, 2018. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.
[2] | Reflects the floating financing rate, as of June 30, 2018, on the notional amount of the forward agreement paid to the counterparty or received from the counterparty, excluding any commissions. Forward Agreements payment is due at termination/maturity.
[3] | For forward agreements, a positive amount represents "long" exposure to the underlying commodity. A negative amount represents "short" exposure to the underlying commodity.
[4] | The positions and counterparties herein are as of June 30, 2018. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.
[5] | Reflects the floating financing rate, as of June 30, 2018, on the notional amount of the swap agreement paid to the counterparty or received from the counterparty, excluding any commissions. Total Return Swap Agreements payment is due at termination/maturity.
[6] | For swap agreements, a positive amount represents "long" exposure to the benchmark index. A negative amount represents "short" exposure to the benchmark index.

X
- Definition Commitment to (deliver)/ receive. + References No definition available. + Details
Name: | ck0001415311_CommitmentToDeliverReceive
Namespace Prefix: | ck0001415311_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Derivative rate received paid percent. + References No definition available. + Details
Name: | ck0001415311_DerivativeRateReceivedPaidPercent
Namespace Prefix: | ck0001415311_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Long (Short) Investment Owned Underlying Face Amount at Market Value + References No definition available. + Details
Name: | ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
Namespace Prefix: | ck0001415311_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Settlement Date One + References No definition available. + Details
Name: | ck0001415311_SettlementDateOne
Namespace Prefix: | ck0001415311_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=50485924&loc=SL6090603-123010 + Details
Name: | us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithCitibankNaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithSocieteGeneraleBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithCitibankBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithSocieteGeneraleBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortGoldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortSilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |