XML 27 R28.htm IDEA: XBRL DOCUMENT v2.4.0.6
Line of Credit Facility - Additional Information (Detail) (USD $)
3 Months Ended
Apr. 30, 2013
Minimum
 
Line of Credit Facility [Line Items]  
Interest rate on cash advances in addition to LIBOR 0.50%
Maximum
 
Line of Credit Facility [Line Items]  
Interest rate on cash advances in addition to LIBOR 1.50%
Amendment | Minimum
 
Line of Credit Facility [Line Items]  
Increase in available credit limit $ 100,000,000
Amendment | Maximum
 
Line of Credit Facility [Line Items]  
Increase in available credit limit 175,000,000
Line Of Credit Facility
 
Line of Credit Facility [Line Items]  
Outstanding letters of credit and stand-by letters of credit 70,042,000
Available credit including accordion feature $ 104,958,000