v2.4.0.6
Fair Value Measurements (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2011
years
Dec. 31, 2011
Contingent Consideration [Member]
Dec. 31, 2010
Contingent Consideration [Member]
Short-term Debt [Line Items]      
Weighted-average expected life of underlying student loans minimum, years 2    
Weighted-average expected life of underlying student loans maximum, years 7    
Annual discount rate used in discounted cash flow model 2.76%    
Auction rate reset, lower range, in days 7    
Auction rate reset, upper range, in days 14    
Auction rate securities year of maturity, lower range 2025    
Auction rate securities year of maturity, higher range 2040    
Auction rate securities annual interest rate, lower range 0.18%    
Auction rate securities annual interest rate, higher range 0.80%    
Bonds received from Greek government $ 63,500,000    
Balance included in transfers into level 3 53,900,000    
Contingent consideration   $ 135,600,000 $ 11,100,000