Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Stock-Based Compensation
Options Available for Grant, Outstanding, Beginning balance	342,500
Options Available for Grant, Options authorized	374,944.00
Options Available for Grant, RSUs granted	(10,000.00)
Options Available for Grant, Options cancelled/forfeited	234,973.00
Options Available for Grant, Outstanding, Ending balance	295,517	342,500
Number of Options, Outstanding, Beginning balance	1,414,730
Number of Options, Options granted	646,900
Number of Options, Options exercised	(230,347)
Number of Options, Options cancelled/forfeited	(235,868)
Number of Options, Outstanding, Ending balance	1,595,415	1,414,730
Number of Options, exercisable	760,459
Number of Options, vested and expected to vest	1,595,415
Weighted - Average Exercise Price Per Share, Options outstanding, Beginning balance	$ 5.28
Weighted - Average Exercise Price Per Share, Options granted	13.87
Weighted - Average Exercise Price Per Share, Options exercised	4.76
Weighted - Average Exercise Price Per Share, Options cancelled/forfeited	6.26
Weighted - Average Exercise Price Per Share, Options outstanding, Ending balance	8.69	$ 5.28
Weighted - Average Exercise Price Per Share, Options exercisable	4.93
Weighted - Average Exercise Price Per Share, Options vested and expected to vest	$ 8.69
Weighted - Average Remaining Contractual Life, Options outstanding	6 years 10 months 24 days	7 years 7 months 6 days
Weighted - Average Remaining Contractual Life, Options exercisable	4 years 1 month 6 days
Weighted - Average Remaining Contractual Life, Options vested and expected to vest	6 years 10 months 24 days
Aggregate Intrinsic Value, Options outstanding	$ 13,406	$ 4,267
Aggregate Intrinsic Value, Options exercised	1,981
Aggregate Intrinsic Value, Options exercisable	9,247
Aggregate Intrinsic Value, Options vested and expected to vest	$ 13,406