v2.4.0.6
MARKETABLE SECURITIES (Details 2) (USD $)
 12 Months Ended
Dec. 31, 2011
investment
Dec. 31, 2010
Dec. 31, 2009
Continuous unrealized loss position      
Fair Value $ 24,631,000 $ 73,723,000  
Gross Unrealized Losses (37,000) (246,000)  
Proceeds from maturities and sales of available-for-sale marketable securities and related gross realized gains and losses      
Proceeds from maturities and sales of available-for-sale marketable securities 600,149,000 768,650,000 293,629,000
Gross realized gains 2,482,000 4,802,000 42,372,000
Gross realized losses (41,000) (19,000) (12,414,000)
Net unrealized gains, net of tax, reclassified from other comprehensive income into earnings 2,800,000 3,200,000 700,000
Number of investments in continuous unrealized loss position for less than 12 months 12    
Corporate debt securities
      
Continuous unrealized loss position      
Fair Value 12,920,000 34,552,000  
Gross Unrealized Losses (15,000) (16,000)  
States of the U.S. and state political subdivisions
      
Continuous unrealized loss position      
Fair Value 11,711,000 39,171,000  
Gross Unrealized Losses $ (22,000) $ (230,000)