Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Share-Based Compensation (Schedule Of Stock Option Assumptions) (Details)

v2.4.0.6
Share-Based Compensation (Schedule Of Stock Option Assumptions) (Details)
12 Months Ended
Dec. 31, 2011
years
Stock Options [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Volatility, minimum 38.25%
Volatility, maximum 39.90%
Expected life, minimum (years) 5.00
Expected life, maximum (years) 5.93
Risk-free interest rate, minimum 4.67%
Risk-free interest rate, maximum 4.72%
Dividend yield rate 0.00%
NV Equity Plan [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Volatility, minimum 33.92%
Volatility, maximum 38.42%
Expected life, minimum (years) 5.33
Expected life, maximum (years) 6.53
Risk-free interest rate, minimum 1.89%
Risk-free interest rate, maximum 4.20%
Dividend yield rate 0.00%