Earnings Per Share - Details of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net loss	$ (983)	$ (1,670)	$ (5,541)	$ (6,501)
Dividends paid to preferred stockholders	(43)		(370)
Net loss available to common stockholders	$ (1,026)	$ (1,670)	$ (5,911)	$ (6,501)
Denominator:
Weighted average shares outstanding – basic	25,020	14,297	20,771	13,221
Weighted average shares outstanding – diluted	25,020	14,297	20,771	13,221
Shares excluded due to an exercise price greater than weighted average stock price for the period	126	1,973	1,086	1,869
Net loss per common share:
Basic	$ (0.04)	$ (0.12)	$ (0.28)	$ (0.49)
Diluted	$ (0.04)	$ (0.12)	$ (0.28)	$ (0.49)