Goodwill and Other Intangible Assets - Additional Information (Details)	3 Months Ended		12 Months Ended
	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jan. 31, 2017 USD ($) Segment	Jan. 31, 2016 USD ($)	Jan. 31, 2015 USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense related to other intangible assets			$ 952,000	$ 387,000	$ 53,000
Number of reporting unit | Segment			1
Goodwill impairment	$ 0	$ 0