Geographical Information - Schedule of Revenue and Property and Equipment by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets
Revenue	$ 44,207	$ 40,982	$ 38,886	$ 38,015	$ 36,033	$ 32,287	$ 30,274	$ 30,274	$ 162,090	$ 128,868	$ 103,102
Property and equipment, net	14,688				13,225				14,688	13,225	12,571
United States
Revenues from External Customers and Long-Lived Assets
Revenue									151,484	120,037	95,345
Property and equipment, net	13,025				10,939				13,025	10,939	10,625
International
Revenues from External Customers and Long-Lived Assets
Revenue									10,606	8,831	7,757
Property and equipment, net	$ 1,663				$ 2,286				$ 1,663	$ 2,286	$ 1,946