Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic:
Net income (loss)	$ (618)	$ 473
Diluted:
Net income (loss)	$ (618)	$ 473
Denominator:
Weighted-average shares outstanding in computing basic net income (loss) per share	17,172,699	16,823,851
Effect of potentially dilutive securities:
Stock awards		1,353,754
Weighted-average shares used in computing diluted net income (loss) per share	17,172,699	18,177,605
Net income (loss) per common share:
Basic	$ (0.04)	$ 0.03
Diluted	$ (0.04)	$ 0.03