CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 112	$ 42
Preferred stock, par value per share	$ 0.10	$ 0.10
Preferred stock, shares authorized	400,000	400,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 0.10	$ 0.10
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	32,213,960	31,819,695
Treasury stock, shares	2,450,634	2,450,634