Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents and Available-For-Sale Securities (Details)

v2.4.0.8
Cash, Cash Equivalents and Available-For-Sale Securities (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2013
item
Jun. 30, 2013
item
Dec. 31, 2012
Jun. 30, 2012
Dec. 31, 2011
Cash, cash equivalents and available-for-sale securities          
Cash, cash equivalents and available-for-sale securities $ 251,641 $ 251,641 $ 298,241    
Cash and cash equivalents 21,868 21,868 33,484 26,151 18,633
Available-for-sale securities 229,773 229,773 264,757    
Cash equivalents and available-for-sale securities          
Amortized Cost 243,655 243,655 273,972    
Gross Unrealized Gains 79 79 135    
Gross Unrealized Losses (62) (62) (53)    
Fair Value 243,672 243,672 274,054    
Years to Maturity          
Within One Year 205,716 205,716      
After One Year Through Two Years 37,956 37,956      
Weighted-average time to maturity of cash equivalents and available-for-sale securities   235 days      
Stated maturity period may be greater than this period and classified as current   1 year      
Proceeds from sale of available-for-sale securities 16,500 16,479      
Investments in unrealized loss position for more than twelve months 0 0 0    
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position          
Number of individual securities in unrealized loss position for twelve months or less 44 44      
Fair Value 98,600 98,600      
Unrealized Losses (62) (62)      
Money market funds
          
Cash, cash equivalents and available-for-sale securities          
Cash, cash equivalents and available-for-sale securities 7,688 7,688 23,936    
Government-sponsored enterprise securities
          
Cash, cash equivalents and available-for-sale securities          
Cash, cash equivalents and available-for-sale securities 92,470 92,470 77,047    
Cash equivalents and available-for-sale securities          
Amortized Cost 92,459 92,459 77,041    
Gross Unrealized Gains 25 25 37    
Gross Unrealized Losses (14) (14) (31)    
Fair Value 92,470 92,470 77,047    
Years to Maturity          
Within One Year 56,069 56,069      
After One Year Through Two Years 36,401 36,401      
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position          
Fair Value 31,495 31,495      
Unrealized Losses (14) (14)      
Corporate bonds and commercial paper
          
Cash, cash equivalents and available-for-sale securities          
Cash, cash equivalents and available-for-sale securities 151,202 151,202 197,007    
Cash equivalents and available-for-sale securities          
Amortized Cost 151,196 151,196 196,931    
Gross Unrealized Gains 54 54 98    
Gross Unrealized Losses (48) (48) (22)    
Fair Value 151,202 151,202 197,007    
Years to Maturity          
Within One Year 149,647 149,647      
After One Year Through Two Years 1,555 1,555      
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position          
Fair Value 67,105 67,105      
Unrealized Losses (48) (48)      
Checking account
          
Cash, cash equivalents and available-for-sale securities          
Cash, cash equivalents and available-for-sale securities $ 281 $ 281 $ 251