v2.4.0.8
Investment Securities (Details 4) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Realized gains (losses) on marketable investment securities      
Realized gains from the sales of available-for-sale marketable investment securities $ 36,300,000 $ 175,200,000 $ 6,700,000
Proceeds from sales of available-for-sale marketable investment securities 177,500,000 601,300,000 1,540,000,000
Fair value of marketable investment securities in a loss position      
Less than 12 months 571,592,000 275,587,000  
12 months or more   12,963,000  
Total 571,592,000 288,550,000  
Unrealized losses on marketable investment securities in a loss position      
Less than 12 months (825,000) (288,000)  
12 or more   (19,000)  
Total $ (825,000) $ (307,000)