Schedule of Investments - Futures Contracts Purchased (Detail)		12 Months Ended
		Dec. 31, 2016 USD ($) Contract		Dec. 31, 2015 USD ($) Contract
ProShares VIX Short-Term Futures ETF [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		$ (468,652)	[1]	$ (1,078,625)	[2]
Cash collateral pledged to cover margin requirements		$ 17,235,855		$ 5,888,545
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires January 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[1]	6,549
Notional Amount at Value	[1]	$ 99,053,625
Unrealized Appreciation (Depreciation)	[1]	$ (2,742,526)
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires February 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[1]	4,560
Notional Amount at Value	[1]	$ 75,582,000
Unrealized Appreciation (Depreciation)	[1]	2,273,874
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires January 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[2]			2,821
Notional Amount at Value	[2]			$ 52,259,025
Unrealized Appreciation (Depreciation)	[2]			$ (958,831)
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires February 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[2]			2,821
Notional Amount at Value	[2]			$ 53,246,375
Unrealized Appreciation (Depreciation)	[2]			(119,794)
ProShares VIX Mid-Term Futures ETF [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		(1,288,245)	[3]	(344,360)	[4]
Cash collateral pledged to cover margin requirements		$ 1,052,615		$ 980,750
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires April 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[3]	474
Notional Amount at Value	[3]	$ 8,733,450
Unrealized Appreciation (Depreciation)	[3]	$ (655,635)
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires May 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[3]	806
Notional Amount at Value	[3]	$ 15,172,950
Unrealized Appreciation (Depreciation)	[3]	$ (628,070)
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires June 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[3]	807
Notional Amount at Value	[3]	$ 15,393,525
Unrealized Appreciation (Depreciation)	[3]	$ (72,915)
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires July 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[3]	332
Notional Amount at Value	[3]	$ 6,523,800
Unrealized Appreciation (Depreciation)	[3]	68,375
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires April 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[4]			235
Notional Amount at Value	[4]			$ 4,547,250
Unrealized Appreciation (Depreciation)	[4]			$ (168,335)
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires May 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[4]			469
Notional Amount at Value	[4]			$ 9,145,500
Unrealized Appreciation (Depreciation)	[4]			$ 10,005
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires June 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[4]			469
Notional Amount at Value	[4]			$ 9,262,750
Unrealized Appreciation (Depreciation)	[4]			$ (135,125)
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires July 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[4]			234
Notional Amount at Value	[4]			$ 4,691,700
Unrealized Appreciation (Depreciation)	[4]			(50,905)
ProShares Ultra VIX Short-Term Futures ETF [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		(7,972,237)	[5]	11,894,466	[6]
Cash collateral pledged to cover margin requirements		$ 71,363,625		$ 62,348,600
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires January 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[5]	38,688
Notional Amount at Value	[5]	$ 585,156,000
Unrealized Appreciation (Depreciation)	[5]	$ (21,567,112)
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires February 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[5]	27,012
Notional Amount at Value	[5]	$ 447,723,900
Unrealized Appreciation (Depreciation)	[5]	13,594,875
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires January 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[6]			29,321
Notional Amount at Value	[6]			$ 543,171,525
Unrealized Appreciation (Depreciation)	[6]			$ 10,546,019
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires February 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[6]			29,320
Notional Amount at Value	[6]			$ 553,415,000
Unrealized Appreciation (Depreciation)	[6]			1,348,447
ProShares Ultra Bloomberg Crude Oil [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		55,358,571	[7]	(72,176,589)	[8]
ProShares Ultra Bloomberg Crude Oil [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements		$ 20,609,600		$ 47,571,810
ProShares Ultra Bloomberg Crude Oil [Member] | WTI Crude Oil - NYMEX, Expires March 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[9]	5,855
Notional Amount at Value	[9]	$ 320,034,300
Unrealized Appreciation (Depreciation)	[9]	5,537,165
ProShares Ultra Bloomberg Crude Oil [Member] | Crude Oil - NYMEX, Expires March 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[10]			11,089
Notional Amount at Value	[10]			$ 423,267,130
Unrealized Appreciation (Depreciation)	[10]			(17,929,314)
ProShares Ultra Bloomberg Natural Gas [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements		$ 7,612,770		$ 7,595,280
ProShares Ultra Bloomberg Natural Gas [Member] | Natural Gas - NYMEX, Expires March 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[11]	2,346
Notional Amount at Value	[11]	$ 86,426,640
Unrealized Appreciation (Depreciation)	[11]	2,536,720
ProShares Ultra Bloomberg Natural Gas [Member] | Natural Gas - NYMEX, Expires March 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[12]			3,288
Notional Amount at Value	[12]			$ 77,695,440
Unrealized Appreciation (Depreciation)	[12]			6,312,879
ProShares Ultra Gold [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		(4,431,107)	[13]	(2,250,595)	[14]
ProShares Ultra Gold [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements		$ 13,200		$ 8,250
ProShares Ultra Gold [Member] | Gold Futures - COMEX, Expires February 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[15]			2
Notional Amount at Value	[15]			$ 212,040
Unrealized Appreciation (Depreciation)	[15]			(5,200)
ProShares Ultra Gold [Member] | Gold Futures - COMEX, Expires February 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[16]	2
Notional Amount at Value	[16]	$ 230,340
Unrealized Appreciation (Depreciation)	[16]	(18,960)
ProShares Ultra Silver [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)		(20,976,189)	[13]	(22,561,101)	[14]
ProShares Ultra Silver [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Cash collateral pledged to cover margin requirements		$ 14,300		$ 17,160
ProShares Ultra Silver [Member] | Silver Futures - COMEX, Expires March 2016 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[17]			3
Notional Amount at Value	[17]			$ 207,045
Unrealized Appreciation (Depreciation)	[17]			$ (9,030)
ProShares Ultra Silver [Member] | Silver Futures - COMEX, Expires March 2017 [Member] | Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Number of Contracts | Contract	[18]	2
Notional Amount at Value	[18]	$ 159,890
Unrealized Appreciation (Depreciation)	[18]	$ (27,360)

[1] Cash collateral in the amount of $17,235,855 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[2] Cash collateral in the amount of $5,888,545 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[3] Cash collateral in the amount of $1,052,615 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[4] Cash collateral in the amount of $980,750 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[5] Cash collateral in the amount of $71,363,625 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[6] Cash collateral in the amount of $62,348,600 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[7] The positions and counterparties herein are as of December 31, 2016. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.

[8] The positions and counterparties herein are as of December 31, 2015. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at anytime.

[9] Cash collateral in the amount of $20,609,600 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[10] Cash collateral in the amount of $47,571,810 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[11] Cash collateral in the amount of $7,612,770 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[12] Cash collateral in the amount of $7,595,280 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[13] The positions and counterparties herein are as of December 31, 2016. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at anytime.

[14] The positions and counterparties herein are as of December 31, 2015. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.

[15] Cash collateral in the amount of $8,250 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[16] Cash collateral in the amount of $13,200 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.

[17] Cash collateral in the amount of $17,160 was pledged to cover margin requirements for open futures contracts as of December 31, 2015.

[18] Cash collateral in the amount of $14,300 was pledged to cover margin requirements for open futures contracts as of December 31, 2016.