Goodwill - Additional Information (Detail) - USD ($)		3 Months Ended
	Jun. 25, 2015	Apr. 30, 2017	Apr. 30, 2016	Jan. 31, 2017
Finite Lived Intangible Assets [Line Items]
Goodwill		$ 26,601,000		$ 26,601,000
Goodwill impairment		$ 0	$ 0
Vis Lab S R L
Finite Lived Intangible Assets [Line Items]
Business acquisition date	Jun. 25, 2015
Cash paid for business acquisition	$ 30,000,000
Goodwill	25,300,000
Intangible assets acquired	4,100,000
Net assets acquired	600,000
Deferred tax liabilities, intangible assets	$ 1,300,000