v2.4.0.6
MARKETABLE SECURITIES (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Available-for-sale marketable securities    
Amortized Cost $ 165,035 $ 560,661
Gross Unrealized Gains 697 3,582
Gross Unrealized Losses (37) (246)
Estimated Fair Value 165,695 563,997
Contractual maturities of debt securities classified as available-for-sale    
Due in one year or less, Amortized Cost 68,375  
Due after one year through five years, Amortized Cost 92,004  
Total, Amortized Cost 160,379  
Due in one year or less, Estimated Fair Value 68,545  
Due after one year through five years, Estimated Fair Value 92,483  
Total, Estimated Fair Value 161,028  
Total debt securities
   
Available-for-sale marketable securities    
Amortized Cost 160,379 547,765
Gross Unrealized Gains 686 1,164
Gross Unrealized Losses (37) (246)
Estimated Fair Value 161,028 548,683
Corporate debt securities
   
Available-for-sale marketable securities    
Amortized Cost 48,621 237,406
Gross Unrealized Gains 99 773
Gross Unrealized Losses (15) (16)
Estimated Fair Value 48,705 238,163
States of the U.S. and state political subdivisions
   
Available-for-sale marketable securities    
Amortized Cost 111,758 110,478
Gross Unrealized Gains 587 373
Gross Unrealized Losses (22) (230)
Estimated Fair Value 112,323 110,621
U.S. Treasury securities
   
Available-for-sale marketable securities    
Amortized Cost   199,881
Gross Unrealized Gains   18
Estimated Fair Value   199,899
Marketable equity security
   
Available-for-sale marketable securities    
Amortized Cost 4,656 12,896
Gross Unrealized Gains 11 2,418
Estimated Fair Value $ 4,667 $ 15,314