Annual report pursuant to Section 13 and 15(d)

Equity (Details)

Equity (Details) (USD $)	12 Months Ended
Equity (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Warrant [Member]
Summary of stock option activities
Number of Units, Beginning balance	9,673,290	12,770,637
Granted	491,928	329,866
Exercised	(2,501,993)	(2,403,429)
Cancellation and Forfeited	(29,167)	(1,023,784)
Number of Units, Ending Balance	7,634,058	9,673,290
Exercisable	7,349,058
Weighted Average Exercise Price, Beginning balance	$ 1.06	$ 0.97
Weighted Average Exercise Price, granted	$ 8.33	$ 7.47
Weighted Average Exercise Price, exercised	$ 0.67	$ 1.58
Weighted Average Exercise Price, forfeited	$ 6.70
Weighted Average Exercise Price, Ending Balance	$ 1.64	$ 1.06
Weighted Average Exercise Price, Exercisable	$ 1.40
Weighted Average Remaining Contractual Term (in years), Outstanding, Beginning balance	4 years 10 months 21 days	4 years 5 months 23 days
Weighted Average Remaining Contractual Term (in years), Issued	7 years 10 months 24 days	6 years 4 months 24 days
Weighted Average Remaining Contractual Term (in years), Outstanding, Ending balance	3 years 11 months 19 days	4 years 10 months 21 days
Weighted Average Remaining Contractual Term (in years), Exercisable	3 years 9 months 4 days
Aggregate Intrinsic Value, Beginning balance	$ 47,396,307	$ 6,114,768
Aggregate Intrinsic Value, Exercised
Aggregate Intrinsic Value, Ending Balance	34,317,224	47,396,307
Aggregate Intrinsic Value, Exercisable	34,283,224
Stock Options [Member]
Summary of stock option activities
Number of Units, Beginning balance	1,985,384	2,330,134
Granted	1,338,100	787,450
Exercised	(310,400)	(16,650)
Cancellation and Forfeited		(1,115,550)
Number of Units, Ending Balance	3,013,084	1,985,384
Exercisable	714,447
Weighted Average Exercise Price, Beginning balance	$ 3.23	$ 0.96
Weighted Average Exercise Price, granted	$ 8.86	$ 6.62
Weighted Average Exercise Price, exercised	$ 0.95	$ 0.78
Weighted Average Exercise Price, Ending Balance	$ 5.98	$ 3.23
Weighted Average Exercise Price, Exercisable	$ 1.20
Weighted Average Remaining Contractual Term (in years), Outstanding, Beginning balance	8 years 4 months 2 days	8 years 10 months 28 days
Weighted Average Remaining Contractual Term (in years), Issued	10 years	10 years
Weighted Average Remaining Contractual Term (in years), Outstanding, Ending balance	8 years 4 months 6 days	8 years 4 months 2 days
Weighted Average Remaining Contractual Term (in years), Exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value, Beginning balance	5,908,696	685,800
Aggregate Intrinsic Value, Exercised
Aggregate Intrinsic Value, Ending Balance	4,728,842	5,908,696
Aggregate Intrinsic Value, Exercisable	$ 3,357,044