XML 19 R55.htm IDEA: XBRL DOCUMENT v2.4.0.6
Financial Instruments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost $ 585,909 $ 183,532    
Unrealized Gains 31       
Unrealized Losses (207)       
Fair Value 585,733 183,532    
Cash and Cash Equivalents 367,515 183,532 93,133 31,364
Short-Term Marketable Securities 118,970       
Long-Term Marketable Securities 99,248       
Level 1 [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 356,512      
Unrealized Gains         
Unrealized Losses         
Fair Value 356,512      
Cash and Cash Equivalents 356,512      
Short-Term Marketable Securities         
Long-Term Marketable Securities         
Level 1 [Member] | Money Market Funds [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 215,052 69,000    
Unrealized Gains          
Unrealized Losses          
Fair Value 215,052 69,000    
Cash and Cash Equivalents 215,052 69,000    
Short-Term Marketable Securities          
Long-Term Marketable Securities          
Level 2 [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 229,397      
Unrealized Gains 31      
Unrealized Losses (207)      
Fair Value 229,221      
Cash and Cash Equivalents 11,003      
Short-Term Marketable Securities 118,970      
Long-Term Marketable Securities 99,248      
Level 2 [Member] | U.S. agency securities [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 13,634      
Unrealized Gains 4      
Unrealized Losses (3)      
Fair Value 13,635      
Short-Term Marketable Securities 7,635      
Long-Term Marketable Securities 6,000      
Level 2 [Member] | Commercial paper [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 48,710      
Unrealized Gains 15      
Unrealized Losses (22)      
Fair Value 48,703      
Cash and Cash Equivalents 9,999      
Short-Term Marketable Securities 38,704      
Level 2 [Member] | Corporate securities [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 162,050      
Unrealized Gains 12      
Unrealized Losses (180)      
Fair Value 161,882      
Cash and Cash Equivalents 1,004      
Short-Term Marketable Securities 67,630      
Long-Term Marketable Securities 93,248      
Level 2 [Member] | Municipal securities [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost 5,003      
Unrealized Losses (2)      
Fair Value 5,001      
Short-Term Marketable Securities 5,001      
Cash [Member]
       
Schedule of cash, cash equivalent and marketable securities        
Amortized Cost, Cash 141,460 114,532    
Unrealized Gains, Cash          
Unrealized Losses, Cash          
Fair Value, Cash 141,460 114,532    
Cash and Cash Equivalents, Cash 141,460 114,532    
Short-Term Marketable Securities, Cash          
Long-Term Marketable Securities, Cash