CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 2,136	$ 1,922	$ 4,228	$ 3,694
Cost of revenue
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	121	29	240	57
Sales and marketing
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	152	41	306	56
Research and development
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	499	298	741	660
General and administrative
Includes stock-based compensation expense as follows:
Total stock-based compensation expense	$ 1,364	$ 1,554	$ 2,941	$ 2,921