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Significant Accounting Policies - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Jan. 31, 2014
Jan. 31, 2013
Jan. 31, 2012
Apr. 30, 2013
Accounting Policies [Line Items]        
Ownership interest in joint venture       51.00%
Anti-dilutive shares excluded from diluted net income per share calculation 181,889   20,000  
Common stock issued in connection with exercise or vesting of equity awards 319,648 337,825 223,000  
Restricted stock awards vesting period, minimum 4 years      
Restricted stock awards vesting period, maximum 5 years      
Wholesale shipping and handling costs $ 54.8 $ 50.7 $ 44.9  
Advertising expense 62.3 54.1 43.8  
Prepaid advertising $ 5.9 $ 5.5    
Minimum
        
Accounting Policies [Line Items]        
Intangible assets, estimated useful lives 3 years      
Maximum
        
Accounting Policies [Line Items]        
Intangible assets, estimated useful lives 15 years      
Stock options, vesting term 10 years