Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock and paid-in capital, par value	$ 0.001	$ 0.001
Common stock and paid-in capital, shares authorized	200,000,000	200,000,000
Common stock and paid-in capital, shares issued	32,906,000	24,296,000
Common stock and paid-in capital, shares outstanding	32,882,000	24,263,000