Annual report pursuant to Section 13 and 15(d)

Consolidated Balance Sheet Detail - Additional Information (Detail)

v3.20.1
Consolidated Balance Sheet Detail - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Jan. 31, 2020
Jul. 31, 2019
Jan. 31, 2020
Jan. 31, 2019
Balance Sheet Related Disclosures [Line Items]        
Impairment charge   $ 0    
Carrying value $ 11,177   $ 11,177 $ 20,990
Loss on sale of fixed assets     5,423  
Property and Equipment [Member]        
Balance Sheet Related Disclosures [Line Items]        
Depreciation expense     900 1,300
Buildings [Member]        
Balance Sheet Related Disclosures [Line Items]        
Impairment charge     1,200  
Carrying value 3,500   $ 3,500 $ 3,467
Buildings [Member] | Massachusetts [Member]        
Balance Sheet Related Disclosures [Line Items]        
Proceeds from sale of building, net of disposal costs 500      
Loss on sale of fixed assets $ 5,400