v2.4.0.8

Investments - Effect of Derivative Instruments on Statements of Operations (Detail) (USD $) | 3 Months Ended
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Mar. 31, 2014 | Mar. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | $ 76,214,916 | $ (230,349,276)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (53,072,999) | 86,306,510
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares UltraShort DJ-UBS Commodity [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (635,695) | 308,498
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 129,934 | (241,421)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares UltraShort DJ-UBS Crude Oil [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (12,278,001) | (6,125,158)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (3,391,572) | (1,500,109)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares UltraShort DJ-UBS Natural Gas [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (9,215,034) | (1,773,421)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 3,437,020 | (3,905,888)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares UltraShort Gold [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (22,149,687) | 12,883,467
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 2,901,049 | (6,992,788)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares UltraShort Silver [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (12,614,405) | 29,204,512
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 9,961,567 | (19,064,897)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares Ultra DJ-UBS Commodity [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 537,342 | (508,897)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (129,206) | 421,315
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares Ultra DJ-UBS Crude Oil [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 21,193,668 | 66,564,325
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 484,711 | (28,737,943)
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares Ultra DJ-UBS Natural Gas [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 16,803,375 | 5,748,194
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 1,805,128 | 17,861,568
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares Ultra Gold [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 23,433,620 | (50,415,205)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (5,199,398) | 24,891,118
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/ or Forward Agreements/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/ or Forward Agreements [Member] | ProShares Ultra Silver [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 73,955,572 | (215,688,548)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (55,636,611) | 137,646,238
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares Short Euro [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (66,588) | (8,000)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 81,131 | 116,769
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares UltraShort Australian Dollar [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (78,609) | 112,030
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (2,139,484) | (195,160)
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares UltraShort Euro [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (12,182,041) | (2,949,680)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 10,024,197 | 26,813,021
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares UltraShort Yen [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (102,730) | 96,886,297
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (24,540,300) | (35,381,549)
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares Ultra Australian Dollar [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (27,427) | (149,275)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 311,205 | 223,960
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares Ultra Euro [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 85,136 | (65,362)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (79,978) | (221,155)
Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Foreign Currency Forward Contracts/ Changes in Unrealized Appreciation/ Depreciation on Foreign Currency Forward Contracts [Member] | ProShares Ultra Yen [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (10,517) | (1,217,971)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 118,080 | 423,734
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares VIX Short-Term Futures ETF [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 15,779,707 | (55,408,949)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 11,625,721 | (8,124,641)
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares VIX Mid-Term Futures ETF [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (5,397,902) | (10,260,171)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | 2,889,479 | (406,019)
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | (3,546,304) | (122,690,073)
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | (5,691,916) | (21,095,534)
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares Short VIX Short-Term Futures ETF [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Realized Gain or (Loss) on Derivatives Recognized in Income | 2,731,436 | 25,204,111
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income | $ (33,756) | $ 3,775,891

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- Definition Change in unrealized appreciation/ depreciation on derivatives recognized in income. + References No definition available. + Details
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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
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