Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Detail)

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Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Detail)
12 Months Ended
Jan. 31, 2019
Buildings [Member]  
Property, Plant and Equipment [Line Items]  
Property plant and equipment useful life 20 years
Office Furniture and Equipment [Member]  
Property, Plant and Equipment [Line Items]  
Property plant and equipment useful life 5 years
Computer Equipment, Software and Demonstration Equipment [Member]  
Property, Plant and Equipment [Line Items]  
Property plant and equipment useful life 3 years
Service and Spare Components [Member]  
Property, Plant and Equipment [Line Items]  
Property plant and equipment useful life 5 years
Leasehold Improvements [Member]  
Property, Plant and Equipment [Line Items]  
Property plant and equipment useful life Shorter of lease term or estimated useful life