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, 2017	Apr. 30, 2016
Numerator:
Net loss	$ (28,901)	$ (22,753)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	39,783	18,574
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.73)	$ (1.22)
Class A Common Stock
Numerator:
Net loss	$ (2,390)	$ 0
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	3,291	0
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.73)	$ 0.00
Class B Common Stock
Numerator:
Net loss	$ (26,511)	$ (22,753)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	36,492	18,574
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.73)	$ (1.22)