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Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Apr. 30, 2020
Oct. 31, 2020
Oct. 31, 2019
Jan. 31, 2020
Segment Reporting Information [Line Items]        
Impairment of intangible assets $ 0      
Aggregate amortization expense   $ 1,300,000 $ 1,300,000  
Klein Associates Inc.        
Segment Reporting Information [Line Items]        
Impairment of indefinite lived intangible assets       $ 760,000
Seamap        
Segment Reporting Information [Line Items]        
Goodwill, impairment $ 2,500,000