Annual report pursuant to Section 13 and 15(d)

Quarterly Results of Operations-Unaudited - Quarterly Results of Operations (Parenthetical) (Detail)

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Quarterly Results of Operations-Unaudited - Quarterly Results of Operations (Parenthetical) (Detail) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2017
Jan. 31, 2017
Jan. 31, 2016
Jan. 31, 2017
Jan. 31, 2016
Schedule Of Quarterly Financial Information [Line Items]          
Loss on impairment of long-lived assets $ 500 $ 23,500 $ 21,500 $ 23,772 $ 21,464
Operating Income (Loss) [Member]          
Schedule Of Quarterly Financial Information [Line Items]          
Loss on impairment of long-lived assets   23,700      
New Hampshire [Member]          
Schedule Of Quarterly Financial Information [Line Items]          
Loss on impairment of long-lived assets   $ 200