Capital Structure	3 Months Ended
Mar. 31, 2019
Equity [Abstract]
Capital Structure	Capital Structure The Company has four classes of authorized common stock. The Class A Common Stock and the Class C Common Stock have one vote per share. The Class B Common Stock and the Class D Common Stock have 10 votes per share. Shares of the Company’s common stock generally vote together as a single class on all matters submitted to a vote of the Company’s stockholders. During the period prior to the Reorganization Transactions and IPO, Class A-2 profits interests and Class B interests in Virtu Financial were issued to Employee Holdco (as defined below) on behalf of certain key employees and stakeholders. In connection with the Reorganization Transactions, all Class A-2 profits interests and Class B interests were reclassified into non-voting common interest units (the “Virtu Financial Units”). As of March 31, 2019 and December 31, 2018, respectively, there were 8,520,755 and 8,760,755 Virtu Financial Units outstanding, respectively, and 240,000 and 3,540,312 Virtu Financial Units and corresponding Class C Common Stock were exchanged into Class A Common Stock, forfeited or repurchased during the three months ended March 31, 2019 and 2018, respectively. Amended and Restated 2015 Management Incentive Plan The Company’s board of directors and stockholders adopted the 2015 Management Incentive Plan, which became effective upon consummation of the IPO, and was subsequently amended and restated following receipt of approval from the Company’s stockholders on June 30, 2017. The Amended and Restated 2015 Management Incentive Plan provides for the grant of stock options, restricted stock units, and other awards based on an aggregate of 16,000,000 shares of Class A Common Stock, subject to additional sublimits, including limits on the total option grant to any one participant in a single year and the total performance award to any one participant in a single year. Acquisition of KCG On the KCG Closing Date, the Company completed the all-cash Acquisition of KCG. In connection with the Acquisition of KCG, the Company issued 8,012,821 shares of the Company’s Class A Common Stock to Aranda Investments Pte. Ltd. (“Aranda”), an affiliate of Temasek Holdings (Private) Limited (“Temasek”), for an aggregate purchase price of approximately $125.0 million and 40,064,103 shares of the Company’s Class A Common Stock to North Island Holdings I, LP (the “North Island Stockholder”) for an aggregate purchase price of approximately $618.7 million, in each case in accordance with terms of an investment agreement in a private placement exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), pursuant to Section 4(a)(2) of the Securities Act. The investment agreements are described in, and the full text thereof is filed as an exhibit to, the Company’s 2018 annual report on Form 10-K filed with the Securities and Exchange Commission on March 1, 2019. Share Repurchase Program In February 2018, the Company's board of directors authorized a new share repurchase program of up to $50.0 million in Class A Common Stock and Virtu Financial Units by March 31, 2019. On July 27, 2018, the Company's board of directors authorized the expansion of the Company's share repurchase program, increasing the total authorized amount by $50.0 million to $100.0 million and extending the duration of the program through September 30, 2019. Since the inception of the program in February 2018, the Company has repurchased approximately 2.6 million shares of Class A Common Stock and Virtu Financial Units for approximately $65.9 million. The Company now has approximately $34.1 million remaining capacity for future purchases of shares of Class A Common Stock and Virtu Financial Units under the program. Pursuant to the program, the Company may repurchase shares from time to time in open market transactions, privately negotiated transactions or by other means. Repurchases may also be made under Rule 10b5-1 plans. The timing and amount of repurchase transactions will be determined by the Company's management based on its evaluation of market conditions, share price, legal requirements and other factors. The program may be suspended, modified or discontinued at any time without prior notice. Secondary Offerings In May 2018, the Company and certain selling stockholders completed a public offering (the “May 2018 Secondary Offering”) of 17,250,000 shares of Class A Common Stock by the Company and certain selling stockholders at a purchase price per share of $27.16 (the offering price to the public of $28.00 per share minus the underwriters’ discount), which included the exercise in full by the underwriters of their option to purchase additional shares in the May 2018 Secondary Offering. The Company sold 10,518,750 shares of Class A Common Stock in the offering, the net proceeds of which were used to purchase an equivalent number of Virtu Financial Units and corresponding shares of Class D Common Stock from TJMT Holdings LLC pursuant to that certain Member Purchase Agreement, entered into on May 15, 2018 by and between the Company and TJMT Holdings LLC. The selling stockholders sold 6,731,250 shares of Class A Common Stock in the May 2018 Secondary Offering, including 2,081,250 shares of Class A Common Stock issued by the Company upon the exercise of vested stock options. In connection with the May 2018 Secondary Offering, the Company, TJMT Holdings LLC, the North Island Stockholder, Havelock Fund Investments Pte. Ltd. (“Havelock”) and Aranda entered into that certain Amendment No. 1 to the Amended and Restated Registration Rights Agreement dated April 20, 2017, by and among the Company, TJMT Holdings LLC, the North Island Stockholder, Havelock, Aranda and certain direct or indirect equityholders of the Company (the “Amended and Restated Registration Rights Agreement”) to add Mr. Vincent Viola and Mr. Michael Viola, directors of the Company, and to confirm that certain other persons (including the Company’s CEO) remain parties to the Amended and Restated Registration Rights Agreement. Employee Exchanges During the three months ended March 31, 2019 and 2018, pursuant to the exchange agreement by and among the Company, Virtu Financial and holders of Virtu Financial Units, certain current and former employees elected to exchange 240,000 and 795,521 units, respectively in Virtu Financial held directly or on their behalf by Virtu Employee Holdco LLC (“Employee Holdco”) on a one-for-one basis for shares of Class A Common Stock. As a result of the completion of the IPO, the Reorganization Transactions, the Secondary Offerings, employee exchanges, and the share issuance in connection with the Acquisition of KCG, the Company holds approximately 57.0% interest in Virtu Financial at March 31, 2019.

Capital Structure

The Company has four classes of authorized common stock. The Class A Common Stock and the Class C Common Stock have one vote per share. The Class B Common Stock and the Class D Common Stock have 10 votes per share. Shares of the Company’s common stock generally vote together as a single class on all matters submitted to a vote of the Company’s stockholders.

During the period prior to the Reorganization Transactions and IPO, Class A-2 profits interests and Class B interests in Virtu Financial were issued to Employee Holdco (as defined below) on behalf of certain key employees and stakeholders. In connection with the Reorganization Transactions, all Class A-2 profits interests and Class B interests were reclassified into non-voting common interest units (the “Virtu Financial Units”). As of March 31, 2019 and December 31, 2018, respectively, there were 8,520,755 and 8,760,755 Virtu Financial Units outstanding, respectively, and 240,000 and 3,540,312 Virtu Financial Units and corresponding Class C Common Stock were exchanged into Class A Common Stock, forfeited or repurchased during the three months ended March 31, 2019 and 2018, respectively.

Amended and Restated 2015 Management Incentive Plan

The Company’s board of directors and stockholders adopted the 2015 Management Incentive Plan, which became effective upon consummation of the IPO, and was subsequently amended and restated following receipt of approval from the Company’s stockholders on June 30, 2017. The Amended and Restated 2015 Management Incentive Plan provides for the grant of stock options, restricted stock units, and other awards based on an aggregate of 16,000,000 shares of Class A Common Stock, subject to additional sublimits, including limits on the total option grant to any one participant in a single year and the total performance award to any one participant in a single year.

Acquisition of KCG

On the KCG Closing Date, the Company completed the all-cash Acquisition of KCG. In connection with the Acquisition of KCG, the Company issued 8,012,821 shares of the Company’s Class A Common Stock to Aranda Investments Pte. Ltd. (“Aranda”), an affiliate of Temasek Holdings (Private) Limited (“Temasek”), for an aggregate purchase price of approximately $125.0 million and 40,064,103 shares of the Company’s Class A Common Stock to North Island Holdings I, LP (the “North Island Stockholder”) for an aggregate purchase price of approximately $618.7 million, in each case in accordance with terms of an investment agreement in a private placement exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), pursuant to Section 4(a)(2) of the Securities Act. The investment agreements are described in, and the full text thereof is filed as an exhibit to, the Company’s 2018 annual report on Form 10-K filed with the Securities and Exchange Commission on March 1, 2019.

Share Repurchase Program

In February 2018, the Company's board of directors authorized a new share repurchase program of up to $50.0 million in Class A Common Stock and Virtu Financial Units by March 31, 2019. On July 27, 2018, the Company's board of directors authorized the expansion of the Company's share repurchase program, increasing the total authorized amount by $50.0 million to $100.0 million and extending the duration of the program through September 30, 2019. Since the inception of the program in February 2018, the Company has repurchased approximately 2.6 million shares of Class A Common Stock and Virtu Financial Units for approximately $65.9 million. The Company now has approximately $34.1 million remaining capacity for future purchases of shares of Class A Common Stock and Virtu Financial Units under the program. Pursuant to the program, the Company may repurchase shares from time to time in open market transactions, privately negotiated transactions or by other means. Repurchases may also be made under Rule 10b5-1 plans. The timing and amount of repurchase transactions will be determined by the Company's management based on its evaluation of market conditions, share price, legal requirements and other factors. The program may be suspended, modified or discontinued at any time without prior notice.

Secondary Offerings

In May 2018, the Company and certain selling stockholders completed a public offering (the “May 2018 Secondary Offering”) of 17,250,000 shares of Class A Common Stock by the Company and certain selling stockholders at a purchase price per share of $27.16 (the offering price to the public of $28.00 per share minus the underwriters’ discount), which included the exercise in full by the underwriters of their option to purchase additional shares in the May 2018 Secondary Offering. The Company sold 10,518,750 shares of Class A Common Stock in the offering, the net proceeds of which were used to purchase an equivalent number of Virtu Financial Units and corresponding shares of Class D Common Stock from TJMT Holdings LLC pursuant to that certain Member Purchase Agreement, entered into on May 15, 2018 by and between the Company and TJMT Holdings LLC. The selling stockholders sold 6,731,250 shares of Class A Common Stock in the May 2018 Secondary Offering, including 2,081,250 shares of Class A Common Stock issued by the Company upon the exercise of vested stock options.

In connection with the May 2018 Secondary Offering, the Company, TJMT Holdings LLC, the North Island Stockholder, Havelock Fund Investments Pte. Ltd. (“Havelock”) and Aranda entered into that certain Amendment No. 1 to the Amended and Restated Registration Rights Agreement dated April 20, 2017, by and among the Company, TJMT Holdings LLC, the North Island Stockholder, Havelock, Aranda and certain direct or indirect equityholders of the Company (the “Amended and Restated Registration Rights Agreement”) to add Mr. Vincent Viola and Mr. Michael Viola, directors of the Company, and to confirm that certain other persons (including the Company’s CEO) remain parties to the Amended and Restated Registration Rights Agreement.

Employee Exchanges

During the three months ended March 31, 2019 and 2018, pursuant to the exchange agreement by and among the Company, Virtu Financial and holders of Virtu Financial Units, certain current and former employees elected to exchange 240,000 and 795,521 units, respectively in Virtu Financial held directly or on their behalf by Virtu Employee Holdco LLC (“Employee Holdco”) on a one-for-one basis for shares of Class A Common Stock.

As a result of the completion of the IPO, the Reorganization Transactions, the Secondary Offerings, employee exchanges, and the share issuance in connection with the Acquisition of KCG, the Company holds approximately 57.0% interest in Virtu Financial at March 31, 2019.