Restructuring Charges - Summary of Activities Related to the Restructuring Plan (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2017		Oct. 31, 2016
Restructuring And Related Activities [Abstract]
Balance as of January 31, 2017	$ 0
Gross charges	1,830
Cash payments	(563)
Restructuring charges	(940)	[1]	$ 0
Balance as of October 31, 2017	$ 327

[1] The non-cash adjustments to restructuring charges primarily consist of the reversal of previously recognized stock-based compensation expense related to awards that will not vest and the reversal of incentive compensation that will not be paid as a result of the restructuring plan.