Stockholders' Equity - Schedule of Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share under option
Outstanding beginning balance, Shares	3,148,006
Granted, Shares	1,332,400
Exercised, Shares	(291,439)
Forfeited, Shares	(528,953)
Outstanding ending balance, Shares	3,660,014	3,148,006
Options exercisable at end of period, Shares	1,574,788
Expected to vest at end of period, Shares	2,085,226
Weighted Average-Exercise Price
Outstanding beginning balance, Weighted-Average Exercise Price	$ 8.93
Granted, Weighted-Average Exercise Price	11.95
Exercised, Weighted-Average Exercise Price	5.28
Forfeited, Weighted-Average Exercise Price	14.80
Outstanding ending balance, Weighted-Average Exercise Price	9.47	$ 8.93
Options exercisable at end of period, Weighted-Average Exercise Price	7.62
Expected to vest at end of period, Weighted-Average Exercise Price	$ 10.88
Weighted-Average Remaining Contractual Term
Outstanding ending balance, Weighted-Average Contractual Life(in years)	8 years
Options exercisable at end of period, Weighted-Average Contractual Life(in years)	6 years 10 months 6 days
Aggregate Intrinsic Value
Outstanding, Aggregate Intrinsic Value	$ 21,932,858	$ 10,437,947
Exercised, Aggregate Intrinsic Value	2,689,563	$ 600,000	$ 2,000,000
Forfeited, Aggregate Intrinsic Value	1,502,894
Options exercisable at end of period, Aggregate Intrinsic Value	$ 12,971,099