Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	120,958,867
Convertible preferred stock, shares issued	0	30,459,574
Convertible preferred stock, shares outstanding	0	30,459,574
Convertible preferred stock, aggregate liquidation preference		$ 226,725
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	400,000,000	153,993,227
Common stock, shares issued	44,456,659	4,090,898
Common stock, shares outstanding	44,456,659	4,090,898