BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit loss	$ 35	$ 42
Preferred shares, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred shares, authorized (in shares)	10,000,000	10,000,000
Preferred shares, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	200,000,000	200,000,000
Common stock, issued (in shares)	27,203,073	27,069,276
Common stock, outstanding (in shares)	27,203,073	27,069,276