The Company	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company Description of the Company Actua Corporation (together with its subsidiaries, "Actua") was formed on March 4, 1996. Prior to Actua’s recent sale of its interests in its three majority-owned businesses, VelocityEHS Holdings Inc. ("VelocityEHS"), Bolt Solutions Inc. ("Bolt") and Folio Dynamics Holdings Inc. ("FolioDynamix"), which together constituted substantially all of Actua’s assets (such sales together, the "Transactions"), Actua was a multi-vertical cloud technology company with software and service offerings that Actua believed created unique and compelling value for its customers and provided transformative efficiency to vertical markets. Actua entered into a Membership Interest Purchase Agreement, dated as of September 23, 2017, by and among Actua, Actua Holdings, Inc. ("Actua Holdings"), Bolt Holdings LLC (f/k/a Arsenal Acquisition Holdings, LLC) ("Bolt Holdings") and Velocity Holdco III Inc. (formerly Arsenal Buyer Inc.), an affiliate of CVC Growth Fund (“CVC”) (such agreement, the “Velocity/Bolt Sale Agreement”). Under the Velocity/Bolt Sale Agreement, CVC agreed to purchase all of Actua’s interests in VelocityEHS and Bolt based on a total enterprise values of $354 million (such transaction, the “Velocity/Bolt Sale”). The Velocity/Bolt Sale was consummated on December 12, 2017 and Actua realized proceeds of approximately $329.0 million in cash. FolioDynamix entered into an Agreement and Plan of Merger, dated as of September 25, 2017, by and among FolioDynamix, Envestnet, Inc. (“Envestnet”), FCD Merger Sub, Inc. and Actua USA Corporation, as the representative of FolioDynamix’s stockholders (such agreement, the “Folio Sale Agreement”). Under the Folio Sale Agreement, Envestnet agreed to acquire FolioDynamix through the merger of FolioDynamix into a wholly-owned subsidiary of Envestnet. This deal was consummated on January 2, 2018 and Actua realized approximately $166.3 million in cash (approximately $1.5 million of which is being held in escrow to satisfy potential future indemnification claims), with the potential to receive up to an additional $11.6 million for final purchase accounting adjustments. At a special meeting of Actua’s stockholders held on December 7, 2017, approximately 99.79% of the shares that were voted, representing 78.13% of Actua’s outstanding common stock, approved the Transactions, which together constituted a sale of substantially all of Actua’s assets. On January 18, 2018, the Board approved a formal plan of dissolution (the "Plan of Dissolution"), subject to stockholder approval. At a special meeting of Actua’s stockholders to be held on April 18, 2018, Actua’s stockholders will be asked to approve the voluntary dissolution and liquidation of Actua pursuant to the Plan of Dissolution. If the Plan of Dissolution is approved by the requisite vote of Actua’s stockholders, Actua will file a Certificate of Dissolution with the Delaware Secretary of State and, thereafter, conduct only business activities relating to winding up and liquidating its business and affairs. Under Delaware law, Actua will continue to exist for three years after Actua’s dissolution or for such longer period as the Delaware Court of Chancery directs, or as may be required to resolve any pending litigation matters, for the purpose of prosecuting and defending suits against Actua and enabling Actua gradually to close its business, to dispose of its property, to discharge its liabilities and to distribute any remaining assets to its stockholders. The Plan of Dissolution also provides for the appointment, at the Board’s discretion, of a manager (the "Manager") to oversee the sale of Actua’s assets and Actua’s liquidation and wind up. The proportionate interests of all of Actua’s stockholders will be fixed on the basis of their respective stock holdings at the close of business on the date the Certificate of Dissolution is filed with the Delaware Secretary of State (the "Final Record Date"). Actua intends to discontinue recording transfers of shares of its common stock on the Final Record Date, and thereafter certificates representing shares of Actua’s common stock will not be assignable or transferable on Actua’s books except by will, intestate succession or operation of law. After the Final Record Date, any distributions made by Actua will be made solely to the stockholders of record as of the close of business on the Final Record Date, except as may be necessary to reflect subsequent transfers recorded on Actua’s books as a result of any assignments by will, intestate succession or operation of law. In light of the dissolution, Actua intends to request permission from the SEC to suspend certain of Actua's reporting obligations under the Exchange Act of 1934 as amended (the "Exchange Act"), and ultimately to terminate the registration of its common stock. On February 1, 2018, Actua distributed $14.89 per share to its stockholders (the "Transaction Distribution"), this equated to approximately $476.0 million and constituted a substantial portion of the net proceeds from the Transactions. If funds are available and to the extent permitted by Delaware law, Actua intends to make additional liquidating distributions from time to time following the effective date of the filing of the Certificate of Dissolution. Actua is unable to predict the precise amount or timing of any additional liquidating distributions (or whether any additional liquidating distributions will occur at all), however, as many of the factors influencing the amount of cash distributed to Actua’s stockholders in additional liquidating distribution(s) and/or the timing of such distributions cannot be currently quantified with certainty and are subject to change. Basis of Presentation As a result of the consummation of the Transactions, FolioDynamix, VelocityEHS and Bolt are presented as discontinued operations in the Consolidated Financial Statements for all periods presented. On October 18, 2016, the sale of GovDelivery Holdings, Inc. ("GovDelivery"), a former majority-owned subsidiary, was consummated (the "GovDelivery Sale"). Accordingly, the financial results and financial position of GovDelivery are presented as discontinued operations in the Consolidated Financial Statements for all periods presented. The Consolidated Financial Statements contained herein include the accounts of Actua Corporation and its wholly-owned subsidiaries and majority-owned subsidiaries, of which, only FolioDynamix remained at December 31, 2017.

The Company

Description of the Company

Actua Corporation (together with its subsidiaries, "Actua") was formed on March 4, 1996. Prior to Actua’s recent sale of its interests in its three majority-owned businesses, VelocityEHS Holdings Inc. ("VelocityEHS"), Bolt Solutions Inc. ("Bolt") and Folio Dynamics Holdings Inc. ("FolioDynamix"), which together constituted substantially all of Actua’s assets (such sales together, the "Transactions"), Actua was a multi-vertical cloud technology company with software and service offerings that Actua believed created unique and compelling value for its customers and provided transformative efficiency to vertical markets.

Actua entered into a Membership Interest Purchase Agreement, dated as of September 23, 2017, by and among Actua, Actua Holdings, Inc. ("Actua Holdings"), Bolt Holdings LLC (f/k/a Arsenal Acquisition Holdings, LLC) ("Bolt Holdings") and Velocity Holdco III Inc. (formerly Arsenal Buyer Inc.), an affiliate of CVC Growth Fund (“CVC”) (such agreement, the “Velocity/Bolt Sale Agreement”). Under the Velocity/Bolt Sale Agreement, CVC agreed to purchase all of Actua’s interests in VelocityEHS and Bolt based on a total enterprise values of $354 million (such transaction, the “Velocity/Bolt Sale”). The Velocity/Bolt Sale was consummated on December 12, 2017 and Actua realized proceeds of approximately $329.0 million in cash.

FolioDynamix entered into an Agreement and Plan of Merger, dated as of September 25, 2017, by and among FolioDynamix, Envestnet, Inc. (“Envestnet”), FCD Merger Sub, Inc. and Actua USA Corporation, as the representative of FolioDynamix’s stockholders (such agreement, the “Folio Sale Agreement”). Under the Folio Sale Agreement, Envestnet agreed to acquire FolioDynamix through the merger of FolioDynamix into a wholly-owned subsidiary of Envestnet. This deal was consummated on January 2, 2018 and Actua realized approximately $166.3 million in cash (approximately $1.5 million of which is being held in escrow to satisfy potential future indemnification claims), with the potential to receive up to an additional $11.6 million for final purchase accounting adjustments.

At a special meeting of Actua’s stockholders held on December 7, 2017, approximately 99.79% of the shares that were voted, representing 78.13% of Actua’s outstanding common stock, approved the Transactions, which together constituted a sale of substantially all of Actua’s assets.

On January 18, 2018, the Board approved a formal plan of dissolution (the "Plan of Dissolution"), subject to stockholder approval. At a special meeting of Actua’s stockholders to be held on April 18, 2018, Actua’s stockholders will be asked to approve the voluntary dissolution and liquidation of Actua pursuant to the Plan of Dissolution. If the Plan of Dissolution is approved by the requisite vote of Actua’s stockholders, Actua will file a Certificate of Dissolution with the Delaware Secretary of State and, thereafter, conduct only business activities relating to winding up and liquidating its business and affairs.

Under Delaware law, Actua will continue to exist for three years after Actua’s dissolution or for such longer period as the Delaware Court of Chancery directs, or as may be required to resolve any pending litigation matters, for the purpose of prosecuting and defending suits against Actua and enabling Actua gradually to close its business, to dispose of its property, to discharge its liabilities and to distribute any remaining assets to its stockholders. The Plan of Dissolution also provides for the appointment, at the Board’s discretion, of a manager (the "Manager") to oversee the sale of Actua’s assets and Actua’s liquidation and wind up.

The proportionate interests of all of Actua’s stockholders will be fixed on the basis of their respective stock holdings at the close of business on the date the Certificate of Dissolution is filed with the Delaware Secretary of State (the "Final Record Date"). Actua intends to discontinue recording transfers of shares of its common stock on the Final Record Date, and thereafter certificates representing shares of Actua’s common stock will not be assignable or transferable on Actua’s books except by will, intestate succession or operation of law. After the Final Record Date, any distributions made by Actua will be made solely to the stockholders of record as of the close of business on the Final Record Date, except as may be necessary to reflect subsequent transfers recorded on Actua’s books as a result of any assignments by will, intestate succession or operation of law. In light of the dissolution, Actua intends to request permission from the SEC to suspend certain of Actua's reporting obligations under the Exchange Act of 1934 as amended (the "Exchange Act"), and ultimately to terminate the registration of its common stock.

On February 1, 2018, Actua distributed $14.89 per share to its stockholders (the "Transaction Distribution"), this equated to approximately $476.0 million and constituted a substantial portion of the net proceeds from the Transactions. If funds are available and to the extent permitted by Delaware law, Actua intends to make additional liquidating distributions from time to time following the effective date of the filing of the Certificate of Dissolution. Actua is unable to predict the precise amount or timing of any additional liquidating distributions (or whether any additional liquidating distributions will occur at all), however, as many of the factors influencing the amount of cash distributed to Actua’s stockholders in additional liquidating distribution(s) and/or the timing of such distributions cannot be currently quantified with certainty and are subject to change.

Basis of Presentation

As a result of the consummation of the Transactions, FolioDynamix, VelocityEHS and Bolt are presented as discontinued operations in the Consolidated Financial Statements for all periods presented.

On October 18, 2016, the sale of GovDelivery Holdings, Inc. ("GovDelivery"), a former majority-owned subsidiary, was consummated (the "GovDelivery Sale"). Accordingly, the financial results and financial position of GovDelivery are presented as discontinued operations in the Consolidated Financial Statements for all periods presented.

The Consolidated Financial Statements contained herein include the accounts of Actua Corporation and its wholly-owned subsidiaries and majority-owned subsidiaries, of which, only FolioDynamix remained at December 31, 2017.