Selected Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 59,104	$ 54,673	$ 52,441	$ 48,334	$ 41,782	$ 38,441	$ 35,292	$ 31,762	$ 214,552	$ 147,277	$ 99,129
Gross profit	45,189	40,888	39,429	36,561	30,976	28,488	25,806	23,212	162,067	108,482	70,926
Net loss	$ (17,300)	$ (18,293)	$ (10,725)	$ (8,250)	$ (16,270)	$ (9,727)	$ (13,304)	$ (11,077)	$ (54,568)	$ (50,378)	$ (29,740)
Net loss per common share, basic and diluted	$ (0.65)	$ (0.72)	$ (0.43)	$ (0.34)	$ (0.67)	$ (0.40)	$ (0.56)	$ (0.47)	$ (2.16)	$ (2.11)	$ (1.31)