Debt - Letters of Credit (Details) - Letter of Credit [Member] - USD ($)
Aug. 01, 2015
Jan. 31, 2015
Trade LCs [Member]    
Debt Instrument [Line Items]    
Letters of credit outstanding $ 0 $ 0
Stand-by LCs [Member]    
Debt Instrument [Line Items]    
Letters of credit outstanding $ 2,800,000 $ 2,500,000