Quarterly report pursuant to Section 13 or 15(d)

Assumptions Used in Black-Scholes Option-Pricing Model (Detail)

v2.3.0.15
Assumptions Used in Black-Scholes Option-Pricing Model (Detail)
3 Months Ended
Sep. 30, 2011
Year
Sep. 30, 2010
Year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Dividend yield 1.40% 1.80%
Expected annualized volatility 23.00% 23.00%
Risk free interest rate 1.40% 1.40%
Expected life 4 4