CONDENSED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 34	$ 47
Notes receivable, allowance	180	61
Notes and other receivables, long-term, allowance	$ 1	$ 2
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	10,985,000	10,990,000
Common stock, shares outstanding	10,985,000	10,990,000