XML 27 R50.htm IDEA: XBRL DOCUMENT v2.4.0.6
Shareholders' Equity (Details 3)
12 Months Ended
Jan. 31, 2013
Jan. 31, 2012
Fair value of stock options granted    
Expected life (years) 5 years 5 years
Minimum [Member]
   
Fair value of stock options granted    
Risk-free interest rate 0.62% 0.94%
Expected volatility 38.74% 39.07%
Expected dividend yield 3.41% 3.50%
Maximum [Member]
   
Fair value of stock options granted    
Risk-free interest rate 1.20% 2.00%
Expected volatility 39.46% 39.43%
Expected dividend yield 3.46% 3.89%