Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Accounts receivable, allowance	$ 660	$ 1,062
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, shares issued (in shares)	220,979,000	204,364,000
Common stock, shares outstanding (in shares)	220,979,000	204,364,000
Class A common stock
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	243,523,831	129,502,000
Common stock, shares outstanding (in shares)	243,524,000	129,502,000
Class B common stock
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	0	91,477,000
Common stock, shares outstanding (in shares)	0	91,477,000