XML 91 R77.htm IDEA: XBRL DOCUMENT v3.19.1
Derivative Financial Instruments and Risk Management - Additional Information (Detail) - USD ($)
12 Months Ended
Jan. 31, 2019
Jan. 31, 2018
Cross Currency Interest Rate Contract [Member]    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Derivative notional amount $ 6,300,000 $ 7,800,000
Maximum remaining maturity of foreign currency derivatives 5 years  
Amount of gain reclassify from Accumulated OCI into income during next 12 months $ 400,000  
Interest Rate Contract [Member]    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Derivative notional amount $ 11,300,000 $ 14,300,000