Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Numerator:
Net loss	$ (25,962)	$ (27,706)	[1],[2],[3]
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	104,203	39,783	[1]
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.25)	$ (0.70)	[1]
Class A Common Stock
Numerator:
Net loss	$ (19,929)	$ (2,292)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	79,988	3,291
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.25)	$ (0.70)
Class B Common Stock
Numerator:
Net loss	$ (6,033)	$ (25,414)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	24,215	36,492
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.25)	$ (0.70)

[1] See Note 2 for a summary of adjustments.

[2] See Note 2 for a summary of adjustments.

[3] See Note 2 for a summary of adjustments.