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Represents a valuation allowance for prepaid research receivables due a company that are expected to be uncollectible.

No definition available.

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Represents the maximum original maturity period of highly liquid investments.

No definition available.

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Represents the portion of gross commissions allocated by clients to pay for research products and other services provided by the third parties.

No definition available.

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Represents the number of criteria to be met for revenue recognition from the subscriptions, maintenance, customer technical support and professional services.

No definition available.

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Represents the number of parties from whom matched book securities are purchased.

No definition available.

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Represents the maximum percentage of the outstanding voting shares of another entity held directly or indirectly by the parent for consolidation of financial statements.

No definition available.

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Gross amount as of the balance sheet date of the receivable from customers, brokers, dealers and clearing organizations for payments allocated for research products and other services provided by the third parties.

No definition available.

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Carrying amount as of the balance sheet date of the receivable from customers, brokers, dealers and clearing organizations for payments allocated for research products and other services provided by the third parties, net of allowance.

No definition available.

Name:	itg_PrepaidResearchReceivableNet
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Name:	itg_PrinciplesOfConsolidationAbstract
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Represents the term of the agreement.

No definition available.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 730

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

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Revenue from providing technology services. The services may include training, installation, engineering or consulting. Consulting services often include implementation support, software design or development, or the customization or modification of the licensed software.

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 210.5-03.1(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 605

-Section 25

-Paragraph 76

-URI http://asc.fasb.org/extlink&oid=22169047&loc=d3e132428-111767

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 5A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=SL6759159-111685