CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Accounts receivable allowance	$ 3,420	$ 3,701
STOCKHOLDERS’ EQUITY (DEFICIT)
Preferred stock, par or stated value (in dollar per share)	$ 0.001	$ 0.001
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par or stated value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares, issued (in shares)	23,117,000	23,117,000
Common stock, shares, outstanding (in shares)	22,926,000	22,892,000
Treasury stock (in shares)	191,000	225,000