Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense related to other intangible assets	$ 977,000	$ 220,000	$ 1,500,000	$ 432,000