Stockholders' Equity - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net loss	$ (9,511)	$ (1,326)	$ (670)	$ 742	$ 189	$ (840)	$ (1,172)	$ 345	$ (10,765)	$ (1,479)	$ (15,306)
Denominator:
Basic and diluted weighted average common shares outstanding (shares)									19,089,402	19,667,891	20,210,260
Basic and diluted net loss per common share (usd per share)	$ (0.50)	$ (0.07)	$ (0.03)	$ 0.04	$ 0.01	$ (0.04)	$ (0.06)	$ 0.02	$ (0.56)	$ (0.08)	$ (0.76)
Restricted stock units
Denominator:
Restricted stock units (shares)									189,862	178,279	90,665