CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 40	$ 143
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	46,767,000	45,804,000
Common stock, shares outstanding (in shares)	46,767,000	45,804,000