Share-based Compensation - Summary of Stock Option Activities (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Number of Stock Options
Number of Options, Options outstanding, beginning of period	629,629
Number of Options, Granted	469,600
Number of Options, Forfeited and cancelled	(278,642)
Number of Options, Options outstanding, end of period	820,587	629,629
Number of Options, Options exercisable, end of period	294,215
Number of Options, Options vested and expected to vest	819,477
Stock Options, Weighted Average Exercise Price
Weighted Average Exercise Price, Options outstanding, beginning of period	$ 6.30
Weighted Average Exercise Price, Granted	2.54
Weighted Average Exercise Price, Forfeited and cancelled	3.38
Weighted Average Exercise Price, Options outstanding, end of period	5.14	$ 6.30
Weighted Average Exercise Price, Options exercisable, end of period	9.27
Weighted Average Exercise Price, Options vested and expected to vest, end of period	$ 5.14
Stock Options, Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years), Options outstanding	8 years 7 months 24 days	8 years 10 months 10 days
Weighted Average Remaining Contractual Term (in years), Options exercisable	7 years 7 months 2 days
Weighted Average Remaining Contractual Term (in years), Options vested and expected to vest	8 years 7 months 21 days