Consolidated Balance Sheet Statement (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Allowances for doubtful accounts	$ 1,247	$ 691
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	3,000,000	4,021,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	97,000,000	80,420,000
Common stock, shares issued	50,184,000	24,855,000
Common stock, shares outstanding	50,184,000	24,855,000