Term Receivables and Trade Accounts Receivable - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
Jul. 31, 2016	Jul. 31, 2015
Disclosure Term Receivables And Trade Accounts Receivable Additional Information [Abstract]
Billing period	30 days
Net proceeds from sale of receivables	$ 29,543	$ 27,562

Disclosure - Term Receivables and Trade Accounts Receivable - Additional Information [Abstract]

No definition available.

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