Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense related to other intangible assets	$ 942,000	$ 212,000	$ 2,400,000	$ 644,000