Related Parties	12 Months Ended
Dec. 31, 2017
Related Party Transactions [Abstract]
Related Parties	Related Parties Actua has provided strategic and operational support to companies in which it held convertible debt and equity ownership interests prior to the Transactions. Actua’s employees generally provided these services. The costs related to employees were paid by Actua and are reflected in "General and administrative" in Actua’s Consolidated Statements of Operations and Comprehensive Income (Loss). Historically, non-management members of Actua’s Board were compensated with cash and equity grants of Actua common stock accounted for in accordance with guidance for equity-based payment compensation. During 2017 and 2016, non-management members of Actua’s Board were compensated exclusively with equity grants of Actua common stock.

Related Parties

12 Months Ended

Dec. 31, 2017

Actua has provided strategic and operational support to companies in which it held convertible debt and equity ownership interests prior to the Transactions. Actua’s employees generally provided these services. The costs related to employees were paid by Actua and are reflected in "General and administrative" in Actua’s Consolidated Statements of Operations and Comprehensive Income (Loss). Historically, non-management members of Actua’s Board were compensated with cash and equity grants of Actua common stock accounted for in accordance with guidance for equity-based payment compensation. During 2017 and 2016, non-management members of Actua’s Board were compensated exclusively with equity grants of Actua common stock.