Annual report pursuant to Section 13 and 15(d)

Short-Term And Long-Term Investments And Restricted Deposits (Narrative) (Details)

v2.4.0.6
Short-Term And Long-Term Investments And Restricted Deposits (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Short-Term And Long-Term Investments And Restricted Deposits [Abstract]      
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of AAA 38.00%    
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of AA- or higher (in hundredths) 76.00%    
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of A- or higher (in hundredths) 99.00%    
Positions from which gross unrealized losses were generated 31    
Total number of positions 410    
Gain from distribution from the Reserve Primary money market fund   $ 3,287  
Impairment loss on Casenet, LLC    5,531   
Impairment of convertible promissory notes   3,531  
Net realized gain related to sales of fixed income investments   2,479  
Investment amortization $ 10,335 $ 10,750 $ 7,209