Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Allowance for accounts receivable	$ 113	$ 104
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	50,000,000	100,000,000
Common stock, shares issued	18,429,350	18,611,289
Common stock, shares outstanding	18,429,350	18,611,289