Stock-based Compensation Plans and Awards - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock-based Compensation Plans and Awards
Stock-based compensation expense	$ 2,704	$ 1,921
Service costs
Stock-based Compensation Plans and Awards
Stock-based compensation expense	371	181
Sales and marketing
Stock-based Compensation Plans and Awards
Stock-based compensation expense	365	80
Product development
Stock-based Compensation Plans and Awards
Stock-based compensation expense	705	592
General and administrative
Stock-based Compensation Plans and Awards
Stock-based compensation expense	$ 1,263	$ 1,068