Segment Information and Geographic Data - Schedule of Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 42,948	$ 30,145	$ 114,971	$ 79,334
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	36,492	26,973	99,370	72,242
Foreign
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 6,456	$ 3,172	$ 15,601	$ 7,092
Sales Revenue | Customer Concentration Risk | Foreign
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue generated outside of the United States	15.00%	11.00%	14.00%	9.00%