Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 20,230	$ 16,162	$ 17,318
Cost of revenue
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	348	237	1,652
Sales and marketing
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	1,675	735	2,011
Research and development
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	1,707	1,937	1,293
General and administrative
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 16,500	$ 13,253	$ 12,362