Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	23,042,492	22,984,608
Common stock, shares outstanding (in shares)	19,690,774	19,613,085
Treasury stock, shares held (in shares)	3,351,718	3,371,523
Allowance for doubtful accounts	$ 884	$ 688