Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Stock-Based Compensation
Options Available for Grant, Outstanding, Beginning balance	342,500
Options Available for Grant, Outstanding, Ending balance	329,331	342,500
Number of Options, Outstanding, Beginning balance	1,414,730
Number of Options, Options granted	197,950
Number of Options, Options exercised	(158,339)
Number of Options, Options cancelled/forfeited	(185,676)
Number of Options, Outstanding, Ending balance	1,268,665	1,414,730
Number of Options, exercisable	752,725
Number of Options, vested and expected to vest	1,268,665
Weighted - Average Exercise Price Per Share, Options outstanding, Beginning balance	$ 5.28
Weighted - Average Exercise Price Per Share, Options granted	8.79
Weighted - Average Exercise Price Per Share, Options exercised	4.63
Weighted - Average Exercise Price Per Share, Options cancelled/forfeited	6.07
Weighted - Average Exercise Price Per Share, Options outstanding, Ending balance	5.76	$ 5.28
Weighted - Average Exercise Price Per Share, Options exercisable	4.82
Weighted - Average Exercise Price Per Share, Options vested and expected to vest	$ 5.76
Weighted - Average Remaining Contractual Life, Options outstanding	7 years 4 months 24 days	7 years 7 months 6 days
Weighted - Average Remaining Contractual Life, Options exercisable	6 years 2 months 12 days
Weighted - Average Remaining Contractual Life, Options vested and expected to vest	7 years 4 months 24 days
Aggregate Intrinsic Value, Options outstanding	$ 18,036	$ 4,267
Aggregate Intrinsic Value, Options exercised	1,216
Aggregate Intrinsic Value, Options exercisable	11,414
Aggregate Intrinsic Value, Options vested and expected to vest	$ 18,036