v3.8.0.1

Statements of Changes in Shareholders' Equity - 9 months ended Sep. 30, 2017 - USD ($)

Total

ProShares VIX Short-Term Futures ETF [Member]

ProShares VIX Mid-Term Futures ETF [Member]

ProShares Short VIX Short-Term Futures ETF [Member]

ProShares Ultra VIX Short-Term Futures ETF [Member]

ProShares UltraShort Bloomberg Crude Oil [Member]

Pro Shares UltraPro 3X Short Crude Oil ETF [Member]

ProShares UltraShort Bloomberg Natural Gas [Member]

ProShares UltraShort Gold [Member]

ProShares UltraShort Silver [Member]

ProShares Short Euro [Member]

ProShares UltraShort Australian Dollar [Member]

ProShares UltraShort Euro [Member]

ProShares UltraShort Yen [Member]

ProShares Ultra Bloomberg Crude Oil [Member]

ProShares UltraPro 3x Crude Oil ETF [Member]

ProShares Ultra Bloomberg Natural Gas [Member]

ProShares Ultra Gold [Member]

ProShares Ultra Silver [Member]

ProShares Ultra Euro [Member]

ProShares Ultra Yen [Member]

Shareholders' equity, beginning of period at Dec. 31, 2016

$ 3,276,337,487

$ 174,160,146

$ 45,818,914

$ 228,075,387

$ 515,758,754

$ 200,958,303

$ 0

$ 4,038,794

$ 63,653,647

$ 23,017,656

$ 15,770,088

$ 16,613,473

$ 349,392,650

$ 276,781,747

$ 933,731,860

$ 0

$ 43,203,386

$ 92,127,200

$ 275,779,940

$ 11,914,585

$ 5,540,957

Addition of shares

7,589,000,140

274,586,934

23,977,024

3,330,265,694

2,109,762,890

398,064,737

22,510,278

9,317,576

22,375,636

22,025,198

41,062,646

69,116,080

1,105,174,037

29,606,619

66,608,730

14,435,007

31,641,699

18,469,355

Redemption of shares

(6,799,453,980)

(112,968,055)

(4,833,130)

(3,090,287,309)

(1,346,739,303)

(404,776,691)

(4,490,543)

(9,976,781)

(39,496,377)

(20,121,187)

(6,278,641)

(4,723,167)

(105,779,074)

(172,018,744)

(1,285,506,788)

(26,336,701)

(34,012,985)

(36,189,978)

(75,235,084)

(19,683,442)

Net addition (redemption) of shares

789,546,160

161,618,879

19,143,894

239,978,385

763,023,587

(6,711,954)

18,019,735

(659,205)

(17,120,741)

1,904,011

(6,278,641)

(4,723,167)

(64,716,428)

(102,902,664)

(180,332,751)

3,269,918

32,595,745

(21,754,971)

(43,593,385)

(1,214,087)

Net investment income (loss)

(12,249,109)

(356,273)

(83,495)

(3,913,203)

(3,866,250)

(426,772)

(59,643)

^[1]

(44,874)

(66,015)

(40,264)

(36,347)

(42,311)

(461,825)

(396,084)

(1,483,954)

(99,140)

^[1]

(190,949)

(160,597)

(474,113)

(26,051)

(20,949)

Net realized gain (loss)

(443,027,657)

(126,203,648)

(19,180,662)

471,123,858

(646,063,604)

49,805,940

232,006

1,755,918

(10,940,120)

(2,693,510)

(1,335,372)

(1,920,783)

(45,338,431)

(17,532,916)

(123,526,841)

3,137,907

(21,041,439)

23,363,236

20,326,492

2,666,306

338,006

Change in net unrealized appreciation/depreciation

(53,961,203)

(17,854,285)

(651,228)

104,609,483

(93,756,755)

(5,398,492)

(2,423,370)

830,801

(99,988)

745,784

(26,290)

(802,007)

(12,255,062)

(7,490,982)

(6,245,549)

1,272,779

(3,507,126)

(3,986,925)

(7,233,752)

364,855

(53,094)

Net income (loss)

(509,237,969)

(144,414,206)

(19,915,385)

571,820,138

(743,686,609)

43,980,676

(2,251,007)

^[1],[2]

2,541,845

(11,106,123)

(1,987,990)

(1,398,009)

(2,765,101)

(58,055,318)

(25,419,982)

(131,256,344)

4,311,546

^[1],[2]

(24,739,514)

19,215,714

12,618,627

3,005,110

263,963

Shareholders' equity, end of period at Sep. 30, 2017

$ 3,556,645,678

$ 191,364,819

$ 45,047,423

$ 1,039,873,910

$ 535,095,732

$ 238,227,025

$ 15,768,728

^[3]

$ 5,921,434

$ 35,426,783

$ 22,933,677

$ 8,093,438

$ 9,125,205

$ 226,620,904

$ 148,459,101

$ 622,142,765

$ 7,581,464

^[3]

$ 51,059,617

$ 89,587,943

$ 244,805,182

$ 13,705,608

$ 5,804,920

[1]	Since the Fund's inception date was January 13, 2017, the Statements of Operations for the three and nine months ended September 30, 2016 have not been provided. See Note 1.
[2]	Since the Fund's inception date was January 13, 2017, the Statement of Cash Flows for the nine months ended September 30, 2016 has not been provided. See Note 1.
[3]	Since the Fund's inception date was January 13, 2017, the Statement of Financial Condition as of December 31, 2016 has not been provided. See Note 1.

X

- Definition

Net addition (redemption) of shares.

+ References

No definition available.

+ Details

Name:	ck0001415311_NetAdditionRedemptionOfShares
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Realized investment gains losses on securities.

+ References

No definition available.

+ Details

Name:	ck0001415311_RealizedInvestmentGainsLossesOnSecurities
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Unrealized gain loss on investments on securities.

+ References

No definition available.

+ Details

Name:	ck0001415311_UnrealizedGainLossOnInvestmentsOnSecurities
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a),(b))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_InvestmentIncomeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_NetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockRepurchasedDuringPeriodValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockholdersEquity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesVixShortTermFuturesEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesVixMidTermFuturesEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesShortVixShortTermFuturesEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortBloombergCrudeOilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraProThreeXShortCrudeOilEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortBloombergNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortGoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortSilverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesShortEuroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortAustralianDollarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortEuroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraShortYenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraBloombergCrudeOilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltrapro3xCrudeOilEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraBloombergNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraGoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraSilverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraEuroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraYenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: