Stockholders’ Equity and Equity-Based Compensation - Summary of non-cash equity-based compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	$ 5,606	$ 5,956
Stock options
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	1,466	1,566
RSUs
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	4,140	4,390
Cost of revenue
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	174	208
Sales and marketing
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	427	1,218
Product development
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	1,477	1,256
General and administrative
Non-cash equity-based compensation expense related to the 2012 Plan and 2012 ESPP
Non-cash equity-based compensation	$ 3,528	$ 3,274