v3.10.0.1
Schedule of Investments - Short-Term U.S. Government and Agency Obligations (Parenthetical) (Detail) - USD ($)
6 Months Ended
Jun. 30, 2018
Dec. 31, 2017
Schedule of Investments [Line Items]    
Total short-term U.S. government and agency obligations, cost $ 1,300,321,650 $ 2,445,970,899
ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 68.00%  
Total short-term U.S. government and agency obligations, cost $ 5,686,543 6,996,595
ProShares Short VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 18.00%  
Total short-term U.S. government and agency obligations, cost $ 92,995,995 494,962,509
ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 80.00%  
Total short-term U.S. government and agency obligations, cost $ 365,929,311 459,543,053
ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 70.00%  
Total short-term U.S. government and agency obligations, cost $ 17,958,439 50,963,586
ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 37.00%  
Total short-term U.S. government and agency obligations, cost $ 3,288,832 6,996,595
ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 107.00%  
Total short-term U.S. government and agency obligations, cost $ 87,844,378 88,890,367
ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 102.00%  
Total short-term U.S. government and agency obligations, cost $ 212,497,644 235,605,469
ProShares Ultra Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 35.00%  
Total short-term U.S. government and agency obligations, cost $ 997,983 1,998,216
ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 66.00%  
Total short-term U.S. government and agency obligations, cost $ 4,988,035 11,984,898
ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 98.00%  
Total short-term U.S. government and agency obligations, cost $ 173,645,496 253,669,155
ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 61.00%  
Total short-term U.S. government and agency obligations, cost $ 4,092,929 3,999,667
ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 80.00%  
Total short-term U.S. government and agency obligations, cost $ 141,643,132 204,788,208
ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 87.00%  
Total short-term U.S. government and agency obligations, cost $ 22,952,432 31,979,626
ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 86.00%  
Total short-term U.S. government and agency obligations, cost $ 19,971,100 18,352,808
ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 96.00%  
Total short-term U.S. government and agency obligations, cost $ 80,832,200 131,844,652
ProShares VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 19.00%  
Total short-term U.S. government and agency obligations, cost $ 21,999,053 134,855,770
ProShares Ultra VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity 12.00%  
Total short-term U.S. government and agency obligations, cost $ 42,998,148 $ 287,546,397
U.S Treasury Bills 1.771% due 07/19/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.771%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S Treasury Bills 1.771% due 07/19/18 [Member] | ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.771%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.831%  
Debt instrument, maturity date [1],[2] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.831%  
Debt instrument, maturity date [1],[3] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.871%  
Debt instrument, maturity date [1],[3] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.871%  
Debt instrument, maturity date [1],[2] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares Ultra Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.871%  
Debt instrument, maturity date [1],[3] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.871%  
Debt instrument, maturity date [1],[3] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.871%  
Debt instrument, maturity date [1],[3] Aug. 09, 2018  
U.S. Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.907%  
Debt instrument, maturity date [1] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.907%  
Debt instrument, maturity date [1] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.907%  
Debt instrument, maturity date [1],[2] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.907%  
Debt instrument, maturity date [1],[2] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.907%  
Debt instrument, maturity date [1],[3] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.907%  
Debt instrument, maturity date [1] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.907%  
Debt instrument, maturity date [1],[3] Aug. 30, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.907%  
Debt instrument, maturity date [1],[3] Aug. 30, 2018  
U.S. Treasury Bills 1.886% due 09/13/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.886%  
Debt instrument, maturity date [1] Sep. 13, 2018  
U.S. Treasury Bills 1.886% due 09/13/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.886%  
Debt instrument, maturity date [1],[3] Sep. 13, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.934%  
Debt instrument, maturity date [1] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.934%  
Debt instrument, maturity date [1],[3] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.934%  
Debt instrument, maturity date [1] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.934%  
Debt instrument, maturity date [1],[2] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 193.40%  
Debt instrument, maturity date [1],[2] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.934%  
Debt instrument, maturity date [1] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.934%  
Debt instrument, maturity date [1],[3] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.934%  
Debt instrument, maturity date [1] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.934%  
Debt instrument, maturity date [1],[4] Oct. 11, 2018  
U.S. Treasury Bills 1.934% due 10/11/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.934%  
Debt instrument, maturity date [1],[4] Oct. 11, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares Short Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.99%  
Debt instrument, maturity date [1] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.99%  
Debt instrument, maturity date [1],[3] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.99%  
Debt instrument, maturity date [1] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.99%  
Debt instrument, maturity date [1],[2] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.99%  
Debt instrument, maturity date [1],[2] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.99%  
Debt instrument, maturity date [1] Nov. 08, 2018  
U.S. Treasury Bills 1.990% due 11/08/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.99%  
Debt instrument, maturity date [1],[3] Nov. 08, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares Short VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.741% due 07/05/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.741%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.787% due 07/19/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.787%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.884%  
Debt instrument, maturity date [1] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.884%  
Debt instrument, maturity date [1] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.884%  
Debt instrument, maturity date [1],[2] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.884%  
Debt instrument, maturity date [1],[2] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.884%  
Debt instrument, maturity date [1],[4] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.884%  
Debt instrument, maturity date [1] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.884%  
Debt instrument, maturity date [1],[3] Aug. 16, 2018  
U.S. Treasury Bills 1.884% due 08/16/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.884%  
Debt instrument, maturity date [1],[4] Aug. 16, 2018  
U.S. Treasury Bills 1.907% due 08/30/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.907%  
Debt instrument, maturity date [1],[3] Aug. 30, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.888%  
Debt instrument, maturity date [1],[3] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.888%  
Debt instrument, maturity date [1] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.888%  
Debt instrument, maturity date [1],[2] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.888%  
Debt instrument, maturity date [1],[2] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.888%  
Debt instrument, maturity date [1] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.888%  
Debt instrument, maturity date [1],[3] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.888%  
Debt instrument, maturity date [1] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.888%  
Debt instrument, maturity date [1],[4] Sep. 13, 2018  
U.S. Treasury Bills 1.888% due 09/13/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.888%  
Debt instrument, maturity date [1],[4] Sep. 13, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.895%  
Debt instrument, maturity date [1] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.895%  
Debt instrument, maturity date [1] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.895%  
Debt instrument, maturity date [1],[2] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.895%  
Debt instrument, maturity date [1],[2] Sep. 18, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.895%  
Debt instrument, maturity date [1] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.895%  
Debt instrument, maturity date [1],[3] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.895%  
Debt instrument, maturity date [1] Sep. 27, 2018  
U.S. Treasury Bills 1.895% due 09/27/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.895%  
Debt instrument, maturity date [1],[4] Sep. 27, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.946%  
Debt instrument, maturity date [1] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.946%  
Debt instrument, maturity date [1] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 1.946%  
Debt instrument, maturity date [1],[2] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 194.60%  
Debt instrument, maturity date [1],[2] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.946%  
Debt instrument, maturity date [1] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.946%  
Debt instrument, maturity date [1],[3] Oct. 25, 2018  
U.S. Treasury Bills 1.946% due 10/25/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 1.946%  
Debt instrument, maturity date [1],[4] Oct. 25, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.036%  
Debt instrument, maturity date [1] Nov. 23, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.036%  
Debt instrument, maturity date [1] Nov. 23, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 2.036%  
Debt instrument, maturity date [1],[2] Nov. 23, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.036%  
Debt instrument, maturity date [1] Nov. 23, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.036%  
Debt instrument, maturity date [1] Nov. 23, 2018  
U.S. Treasury Bills 2.036% due 11/23/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.036%  
Debt instrument, maturity date [1] Nov. 23, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares Ultra Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 2.049%  
Debt instrument, maturity date [1],[3] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 2.049%  
Debt instrument, maturity date [1],[2] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.049%  
Debt instrument, maturity date [1] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 2.049%  
Debt instrument, maturity date [1],[3] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.049%  
Debt instrument, maturity date [1] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 2.049%  
Debt instrument, maturity date [1],[4] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 2.049%  
Debt instrument, maturity date [1],[4] Dec. 06, 2018  
U.S. Treasury Bills 1.890% due 09/13/18 [Member] | ProShares Ultra Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.89%  
Debt instrument, maturity date [1] Sep. 13, 2018  
U.S. Treasury Bills 1.890% due 09/13/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 1.89%  
Debt instrument, maturity date [1],[3] Sep. 13, 2018  
United States Treasury Bills One Point Seven Three Seven Percentage Due July Five Two Thousand And Eighteen [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.737%  
Debt instrument, maturity date [1] Jul. 05, 2018  
U.S. Treasury Bills 1.795% due 07/19/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.795%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares Ultra Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 2.049%  
Debt instrument, maturity date [1] Dec. 06, 2018  
U.S. Treasury Bills 2.049% due 12/06/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[2] 2.049%  
Debt instrument, maturity date [1],[2] Dec. 06, 2018  
U.S. Treasury Bills 1.783% due 07/19/18 [Member] | ProShares Ultra Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.783%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 1.783% due 07/19/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.783%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 1.785% due 07/19/18 [Member] | ProShares Ultra Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.785%  
Debt instrument, maturity date [1] Jul. 19, 2018  
U.S. Treasury Bills 1.785% due 07/19/18 [Member] | ProShares UltraShort Euro [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.785%  
Debt instrument, maturity date [1] Jul. 19, 2018  
US Treasury Bills 1.737% due 07/05/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.737%  
Debt instrument, maturity date [1] Jul. 05, 2018  
US Treasury Bills 1.737% due 07/05/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.737%  
Debt instrument, maturity date [1] Jul. 05, 2018  
US Treasury Bills 1.737% due 07/05/18 [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.737%  
Debt instrument, maturity date [1] Jul. 05, 2018  
United States Treasury Bills 1.792% due 07/19/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.792%  
Debt instrument, maturity date [1] Jul. 19, 2018  
US Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
US Treasury Bills 1.831% due 08/02/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.831%  
Debt instrument, maturity date [1] Aug. 02, 2018  
US Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
US Treasury Bills 1.871% due 08/09/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.871%  
Debt instrument, maturity date [1] Aug. 09, 2018  
US Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Australian Dollar [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.907%  
Debt instrument, maturity date [1] Aug. 30, 2018  
US Treasury Bills 1.907% due 08/30/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.907%  
Debt instrument, maturity date [1] Aug. 30, 2018  
United States Treasury Bills 1.786% due 07/19/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.786%  
Debt instrument, maturity date [1] Jul. 19, 2018  
United States Treasury Bills 2.036% due 11/23/18 [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[3] 2.036%  
Debt instrument, maturity date [1],[3] Nov. 23, 2018  
United States Treasury Bills 2.036% due 11/23/18 [Member] | ProShares UltraShort Yen [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1],[4] 2.036%  
Debt instrument, maturity date [1],[4] Nov. 23, 2018  
US Treasury Bills 1.799% due 07/19/18 [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.799%  
Debt instrument, maturity date [1] Jul. 19, 2018  
US Treasury Bills 1.743% due 07/05/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.743%  
Debt instrument, maturity date [1] Jul. 05, 2018  
US Treasury Bills 1.771% due 07/19/18 [Member] | ProShares UltraShort Silver [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.771%  
Debt instrument, maturity date [1] Jul. 19, 2018  
Federal Home Loan Discount Notes 1.551% due 07/02/18 [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 1.551%  
Debt instrument, maturity date [1] Jul. 02, 2018  
US Treasury Bills One Point Seven Nine Five Percentage Due July Nineteen Two Thousand and Eighteen [Member] | ProShares UltraShort Gold [Member]    
Schedule of Investments [Line Items]    
Short-term U.S. government and agency obligations percentage of shareholders' equity [1] 0.01792%  
Debt instrument, maturity date [1] Jul. 19, 2018  
[1] Rates shown represent discount rate at the time of purchase.
[2] All or partial amount pledged as collateral for forward agreements.
[3] All or partial amount pledged as collateral for swap agreements.
[4] All or partial amount pledged as collateral for foreign currency forward contracts.