CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Oct. 31, 2019	Jan. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	625,000,000	625,000,000
Common stock, shares issued	63,667,275	60,455,381
Common stock, shares outstanding	63,667,275	60,455,381