CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 3,747	$ 2,136	$ 7,344	$ 4,228
Cost of revenue
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	410	121	715	240
Sales and marketing
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	505	152	895	306
Research and development
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	307	499	580	741
General and administrative
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 2,525	$ 1,364	$ 5,154	$ 2,941