BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 19	$ 0
Notes receivable, allowance	9	0
Notes and other receivables, long-term, allowance	$ 9	$ 0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	1,070,000
Common stock, shares issued	10,933,000	1,070,000
Common stock, shares outstanding	10,933,000	1,070,000