Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Stock Option Activity (Details)

v3.8.0.1
Stockholders' Equity - Summary of Stock Option Activity (Details) - Stock Options - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Number of Shares, Outstanding beginning balance 2,379,444  
Number of Shares, Forfeited / Cancelled (24,582)  
Number of Shares, Exercised (416,416)  
Number of Shares, Outstanding ending balance 1,938,446 2,379,444
Number of Shares, Exercisable ending balance 1,529,689  
Number of Shares, Vested and expected to vest ending balance 1,928,671  
Weighted Average Exercise Price, Outstanding beginning balance $ 1.02 $ 1.00
Weighted Average Exercise Price, Forfeited / Cancelled 1.43  
Weighted Average Exercise Price, Exercised 0.86  
Weighted Average Exercise Price, Exercisable ending balance 0.81  
Weighted Average Exercise Price, Vested and expected to vest ending balance $ 1.02  
Weighted Average Remaining Contractual Life (in years), Outstanding balance 5 years 8 months 8 days 5 years 3 months 18 days
Weighted Average Remaining Contractual Life (in years), Exercisable balance 4 years 9 months 25 days  
Weighted Average Remaining Contractual Life (in years), Vested and expected to vest balance 5 years 8 months 1 day  
Aggregate Intrinsic Value, Outstanding balance $ 6,550,748 $ 15,472,456
Aggregate Intrinsic Value, Exercisable balance 5,489,827  
Aggregate Intrinsic Value, Vested and expected to vest balance $ 6,525,894