Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-Based Compensation
Options Available for Grant, Outstanding, Beginning balance	55,330	106,468
Options Available for Grant, Options authorized	785,364	24,956
Options Available for Grant, Outstanding, Ending balance	342,500	55,330	106,468
Number of Options, Outstanding, Beginning balance	927,175	852,639
Number of Options, Options granted	563,523	123,830
Number of Options, Options exercised	(10,639)	(1,558)
Number of Options, Options cancelled/forfeited	(65,329)	(47,736)
Number of Options, Outstanding, Ending balance	1,414,730	927,175	852,639
Number of Options, exercisable	729,746
Number of Options, vested and expected to vest	1,414,732
Weighted - Average Exercise Price Per Share, Options outstanding, Beginning balance	$ 4.43	$ 4.42
Weighted - Average Exercise Price Per Share, Options granted	13.20	4.50
Weighted - Average Exercise Price Per Share, Options exercised	4.43	4.42
Weighted - Average Exercise Price Per Share, Options cancelled/forfeited	4.71	4.42
Weighted - Average Exercise Price Per Share, Options outstanding, Ending balance	5.28	$ 4.43	$ 4.42
Weighted - Average Exercise Price Per Share, Options exercisable	4.52
Weighted - Average Exercise Price Per Share, Options vested and expected to vest	$ 5.28
Weighted - Average Remaining Contractual Life, Options outstanding	7 years 7 months 6 days	7 years 3 months 18 days	8 years
Weighted - Average Remaining Contractual Life, Options exercisable	6 years 1 month 6 days
Weighted - Average Remaining Contractual Life, Options vested and expected to vest	7 years 7 months 6 days
Aggregate Intrinsic Value, Options outstanding	$ 4,267	$ 6,500
Aggregate Intrinsic Value, Options exercised	114	$ 11
Aggregate Intrinsic Value, Options exercisable	2,752
Aggregate Intrinsic Value, Options vested and expected to vest	$ 4,267