v3.21.1

Significant Accounting Policies - Cut-off Times and Times of Calculation of Funds' Final Net Asset Value for Creation and Redemption of Fund Shares (Detail) | 3 Months Ended
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Mar. 31, 2021
ProShares UltraShort Silver [Member] |  |
Net Asset Value [Line Items] |  |
Create/Redeem Cut-off | 1:00 p.m. | [1]
NAV Calculation Time | 1:25 p.m. |
NAV Calculation Date | March 31, 2021 |
ProShares UltraShort Gold [Member] |  |
Net Asset Value [Line Items] |  |
Create/Redeem Cut-off | 1:00 p.m. | [1]
NAV Calculation Time | 1:30 p.m. |
NAV Calculation Date | March 31, 2021 |
ProShares UltraShort Bloomberg Natural Gas [Member] |  |
Net Asset Value [Line Items] |  |
Create/Redeem Cut-off | 2:00 p.m. | [1]
NAV Calculation Time | 2:30 p.m. |
NAV Calculation Date | March 31, 2021 |
ProShares UltraShort Yen [Member] |  |
Net Asset Value [Line Items] |  |
Create/Redeem Cut-off | 3:00 p.m. | [1]
NAV Calculation Time | 4:00 p.m. |
NAV Calculation Date | March 31, 2021 |
ProShares VIX Short-Term Futures ETF [Member] |  |
Net Asset Value [Line Items] |  |
Create/Redeem Cut-off | 2:00 p.m. | [1],[2]
NAV Calculation Time | 4:00 p.m. | [2]
NAV Calculation Date | March 31, 2021 | [2]
[1] | Although the Funds’ shares may continue to trade on secondary markets subsequent to the calculation of the final NAV, these times represent the final opportunity to transact in creation or redemption units for the three months ended March 31, 2021.
[2] | On Monday, October 26, 2020 each Fund changed its NAV calculation time from 4:15 p.m. (Eastern Time) to 4:00 p.m. (Eastern Time). Please see Note 8 in these Notes to Financial Statements for more information.

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