| Income Tax Disclosure [Abstract] | Period [Axis] | 
|---|
2016-01-01 - 2016-12-31  | 
|---|
Income Tax Disclosure [Abstract]  |    | 
Schedule of Components of Income Tax Expense (Benefit)  | Total income tax (benefit) expense from continuing operations was allocated as follows:    |   |  |  |  |  |  |  |  |  |  |  |  |  (in thousands)  | Year ended December 31,  |     | 2016  |    | 2015  |    | 2014  |  Current taxes:  |    |    |    |    |    |  Federal taxes  | $  | (15,758  | )  |    | $  | (144  | )  |    | $  | (6,352  | )  |  State taxes  | 597  | 
 
  |    | 20  | 
 
  |    | 93  | 
 
  |  Foreign taxes  | 47  | 
 
  |    | 184  | 
 
  |    | 295  | 
 
  |  Current taxes  | $  | (15,114  | )  |    | $  | 60  | 
 
  |    | $  | (5,964  | )  |  Deferred taxes:  |    |    |    |    |    |  Federal taxes  | $  | —  | 
 
  |    | $  | —  | 
 
  |    | $  | (1,319  | )  |  State taxes  | 1,898  | 
 
  |    | 253  | 
 
  |    | (3,181  | )  |  Foreign taxes  | 6  | 
 
  |    | (20  | )  |    | (64  | )  |  Deferred taxes  | $  | 1,904  | 
 
  |    | $  | 233  | 
 
  |    | $  | (4,564  | )  |  Income tax (benefit) expense  | $  | (13,210  | )  |    | $  | 293  | 
 
  |    | $  | (10,528  | )  |  
     | 
Schedule of Deferred Tax Assets and Liabilities  | Actua’s net deferred tax assets (liabilities) consists of the following:  |   |  |  |  |  |  |  |  |  (in thousands)  | As of December 31,  |     | 2016  |    | 2015  |  Deferred tax assets:  |    |    |    |  Net operating loss and capital loss carryforward - 382 limited  | $  | 45,606  | 
 
  |    | $  | 57,158  | 
 
  |  Net operating loss carryforward - not 382 limited  | 73,003  | 
 
  |    | 60,414  | 
 
  |  State net operating loss carryforward, net  | 4,361  | 
 
  |    | 2,844  | 
 
  |  Capital loss carryforward - not 382 limited  | —  | 
 
  |    | 48,071  | 
 
  |  Company basis difference  | 22,984  | 
 
  |    | 20,150  | 
 
  |  Reserves and accruals  | 3,703  | 
 
  |    | 3,293  | 
 
  |  Equity-based compensation expense  | 14,057  | 
 
  |    | 16,105  | 
 
  |  AMT and other credits  | 81  | 
 
  |    | 81  | 
 
  |  Other, net  | 2,085  | 
 
  |    | 2,405  | 
 
  |  Total deferred tax assets  | 165,880  | 
 
  |    | 210,521  | 
 
  |  Valuation allowance  | (147,197  | )  |    | (187,757  | )  |  Total deferred tax assets, net of valuation allowance  | 18,683  | 
 
  |    | 22,764  | 
 
  |  Deferred tax liabilities:  | 
 
  | 
 
  |    | 
 
  | 
 
  |  Intangible assets  | (17,921  | )  |    | (20,130  | )  |  Total deferred tax liabilities  | (17,921  | )  |    | (20,130  | )  |  Total net deferred tax assets  | $  | 762  | 
 
  |    | $  | 2,634  | 
 
  |  
     | 
Schedule of Effective Income Tax Rate Reconciliation  | The effective tax rate, for continuing operations, differs from the federal statutory rate as follows:  |   |  |  |  |  |  |  |  |  |     | Year ended December 31,  |     | 2016  |    | 2015  |    | 2014  |  Tax expense (benefit) at statutory rate  | (35.0  | )%  |    | (35.0  | )%  |    | (35.0  | )%  |  Foreign and state taxes  | 3.1  |  %  |    | 0.5  |  %  |    | 6.2  |  %  |  Non-deductible expenses and other  | 1.4  |  %  |    | 15.5  |  %  |    | 7.2  |  %  |  Valuation allowance  | (1.4  | )%  |    | 19.3  |  %  |    | —  |  %  |    Effective tax rate  | (31.9  | )%  |    | 0.3  |  %  |    | (21.6  | )%  |  
     | 
Schedule of Unrecognized Tax Benefits Roll Forward  | The following is a roll forward of our total gross unrecognized tax benefits, which if reversed would impact the effective tax rate, for the year ended December 31, 2016: 
 
  |   |  |  |  |  |  (in thousands)  |    | 2016  |  Balance as of January 1  |    | $  | —  | 
 
  |     |    |    |  Tax positions related to the current year:  |    |    |  Additions  |    | 257  | 
 
  |  Reductions  |    | —  | 
 
  |     |    |    |  Tax positions related to the prior years:  |    |    |  Additions  |    | —  | 
 
  |  Reductions  |    | —  | 
 
  |  Settlements  |    | —  | 
 
  |  Lapses in statutes of limitations  |    | —  | 
 
  |     |    |    |  Balance as of December 31  |    | $  | 257  | 
 
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