Stock Options, Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Unamortized Stock Compensation Expense [Abstract]
Unamortized stock compensation expense | $	$ 10,353,101
Period for recognition	1 year 4 months 20 days
The Plans [Member] | Stock Options [Member]
Number of Shares [Roll Forward]
Options outstanding, beginning balance (in shares) | shares	4,302,267
Granted (in shares) | shares	1,061,400
Exercised (in shares) | shares	(63,639)
Forfeited (in shares) | shares	(133,517)
Options outstanding, ending balance (in shares) | shares	5,166,511
Vested and expected to vest (in shares) | shares	5,077,867
Exercisable (in shares) | shares	2,810,161
Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (in dollars per share) | $ / shares	$ 5.19
Granted (in dollars per share) | $ / shares	7.81
Exercised (in dollars per share) | $ / shares	4.62
Forfeited (in dollars per share) | $ / shares	5.79
Options outstanding, ending balance (in dollars per share) | $ / shares	5.72
Vested and expected to vest (in dollars per share) | $ / shares	5.68
Exercisable (in dollars per share) | $ / shares	$ 4.22
Remaining Contractual Life and Aggregate Intrinsic Value [Abstract]
Options outstanding, weighted average remaining contractual life	7 years 9 months 11 days
Options outstanding, aggregate intrinsic value | $	$ 24,994,623
Vested and expected to vest, weighted average contractual life	7 years 9 months 4 days
Vested and expected to vest, aggregate intrinsic value | $	$ 24,747,792
Exercisable, weighted average contractual life	6 years 11 months 8 days
Exercisable, aggregate intrinsic value | $	$ 17,557,732