v2.4.0.6
Fair Value Of Financial Instruments (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2011
Mar. 26, 2011
Schedule of Available-for-sale Securities [Line Items]    
Minimum maturity period of investments to be classified as available-for-sale securities, days 90  
Gross unrealized losses $ 76 $ 47
Amortized costs 160,394 215,037
29 Different Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Gross unrealized losses 76  
Amortized costs 62,300  
Number of securities 29  
28 Different Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Gross unrealized losses   47
Amortized costs   $ 61,800
Number of securities   28