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Other Assets - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Jan. 31, 2016
Jan. 31, 2015
Jan. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]      
Purchases of cost method investments $ 16,550 $ 10,000 $ 2,000