Stock Options, Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Unamortized Stock Compensation Expense [Abstract]
Unamortized stock compensation expense | $	$ 13,553,683
Period for recognition	2 years 6 months 22 days
Stock Options [Member]
Number of Shares [Roll Forward]
Options outstanding, beginning balance (in shares) | shares	5,316,511
Granted (in shares) | shares	1,165,400
Exercised (in shares) | shares	(30,666)
Forfeited (in shares) | shares	(63,750)
Options outstanding, ending balance (in shares) | shares	6,387,495
Vested and expected to vest (in shares) | shares	6,387,495
Exercisable (in shares) | shares	3,898,218
Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (in dollars per share) | $ / shares	$ 5.84
Granted (in dollars per share) | $ / shares	9.16
Exercised (in dollars per share) | $ / shares	3.00
Forfeited (in dollars per share) | $ / shares	8.21
Options outstanding, ending balance (in dollars per share) | $ / shares	6.44
Vested and expected to vest (in dollars per share) | $ / shares	6.44
Exercisable (in dollars per share) | $ / shares	$ 5.02
Weighted Average Remaining Contractual Life and Aggregate Intrinsic Value [Abstract]
Options outstanding, weighted average remaining contractual life	7 years 3 months 25 days
Vested and expected to vest, weighted average remaining contractual life	7 years 3 months 25 days
Exercisable, weighted average remaining contractual life	6 years 4 months 24 days
Options outstanding, aggregate intrinsic value | $	$ 27,951,302
Vested and expected to vest, aggregate intrinsic value | $	27,951,302
Exercisable, aggregate intrinsic value | $	$ 22,525,438