Schedule of Investments - Futures Contracts Sold (Parenthetical) (Detail) - Futures Contracts Sold [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
ProShares Short VIX Short-Term Futures ETF [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	$ 55,323,984	$ 123,528,405
ProShares UltraShort Bloomberg Crude Oil [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	4,931,520	10,154,430
ProShares UltraShort Bloomberg Natural Gas [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	710,655	2,046,660
ProShares UltraShort Gold [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	13,200	8,250
ProShares UltraShort Silver [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	14,300	11,440
ProShares Short Euro [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	402,600	503,745
ProShares UltraShort Australian Dollar [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements	$ 914,760	$ 57,065