Segments - Summary of Revenue by Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 52,367	$ 46,996	$ 45,225	$ 43,931	$ 44,320	$ 40,627	$ 38,779	$ 36,843	$ 188,519	$ 160,569	$ 129,251
Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									135,289	120,306	101,192
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									43,661	33,800	22,296
APAC
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 9,569	$ 6,463	$ 5,763