CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$ 2,668	$ 2,745
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, issued	5,000,000	5,000,000
Preferred stock, outstanding	5,000,000	5,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	23,794,000	23,707,000
Common stock, shares outstanding	22,300,000	22,230,000
Treasury stock, shares	1,494,000	1,477,000