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

Share-Based Compensation (Summary Of NV Equity Plan Activity) (Details)

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Share-Based Compensation (Summary Of NV Equity Plan Activity) (Details) (USD $)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Share-Based Compensation [Abstract]      
Options outstanding at beginning, Number of Options 2,283,541 2,575,000 2,887,500
Options outstanding at beginning, Weighted Average Exercise Price         
Forfeitures, Number of Options (150,000) (612,500) (312,500)
Forfeitures, Weighted Average Exercise Price         
Options exercised during year, Number of Options (100,000)    
Options exercised during year, Weighted Average Exercise Price $ 2.95    
Options issued during year, Number of Options 23,662 321,041  
Options issued during year, Weighted Average Exercise Price $ 11.29 $ 22.54  
Options outstanding at ending, Number of Options 2,057,203 2,283,541 2,575,000
Options outstanding at ending, Weighted Average Exercise Price