v3.8.0.1

Significant Accounting Policies - Cut-off Times and Times of Calculation of Funds' Final Net Asset Value for Creation and Redemption of Fund Shares (Detail)	9 Months Ended
	Sep. 30, 2017
ProShares UltraShort Silver [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	6:30 a.m.
NAV Calculation Time	7:00 a.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Silver [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	6:30 a.m.
NAV Calculation Time	7:00 a.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Gold [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	9:30 a.m.
NAV Calculation Time	10:00 a.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Gold [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	9:30 a.m.
NAV Calculation Time	10:00 a.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Bloomberg Crude Oil [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Bloomberg Crude Oil [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
Pro Shares UltraPro 3X Short Crude Oil ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
ProShares UltraPro 3x Crude Oil ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Bloomberg Natural Gas [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Bloomberg Natural Gas [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	2:30 p.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Australian Dollar [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares Short Euro [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Euro [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Euro [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares UltraShort Yen [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra Yen [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	3:00 p.m.
NAV Calculation Time	4:00 p.m.
NAV Calculation Date	September 30, 2017
ProShares VIX Short-Term Futures ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	4:15 p.m.
NAV Calculation Date	September 30, 2017
ProShares Short VIX Short-Term Futures ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	4:15 p.m.
NAV Calculation Date	September 30, 2017
ProShares Ultra VIX Short-Term Futures ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	4:15 p.m.
NAV Calculation Date	September 30, 2017
ProShares VIX Mid-Term Futures ETF [Member]
Net Asset Value [Line Items]
Create/Redeem Cut-off	2:00 p.m.
NAV Calculation Time	4:15 p.m.
NAV Calculation Date	September 30, 2017

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