Capital Structure - Amended and Restated Investment Technology Group, Inc. 2007 Omnibus Equity Compensation Plan (Details) - Assumed Awards - Class A	Mar. 01, 2019 shares
Class of Stock [Line Items]
Number of shares of stock authorized	2,497,028
Number of shares remaining to be issued	1,230,406

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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