Stock Based Compensation - Summary of Activity under Incentive Plan (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Outstanding, Number of Shares, Beginning Balance | shares	857,311
Number of Shares, Options Granted | shares	38,600
Number of Shares, Options Exercised | shares	(6,250)
Number of Shares, Options Cancelled or forfeited | shares	(22,113)
Outstanding, Number of Shares, Ending Balance | shares	867,548
Outstanding, Weighted Average Exercise Price Per Share, Beginning Balance | $ / shares	$ 9.49
Weighted Average Exercise Price Per Share, Options Granted | $ / shares	5.88
Weighted Average Exercise Price Per Share, Options Exercised | $ / shares	3.72
Weighted Average Exercise Price Per Share, Options Cancelled or forfeited | $ / shares	11.80
Outstanding, Weighted Average Exercise Price Per Share, Ending Balance | $ / shares	$ 9.31
Aggregate Intrinsic Value, Ending Balance | $	$ 78