Goodwill and Other Intangible Assets (Details) 1 (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Mar. 31, 2013
P B M
Mar. 31, 2013
H C I T
Dec. 31, 2012
H C I T
Goodwill [Roll Forward]        
Goodwill, Beginning Balance $ 4,478,038 $ 4,458,373 $ 19,665 $ 19,665
Goodwill, Measurement period adjustment 280 [1] 280 [1]    
Goodwill, Ending Balance $ 4,478,318 $ 4,458,653 $ 19,665 $ 19,665
[1] Adjustments to the fair value of assets acquired and liabilities assumed for recent acquisitions during the measurement period. The measurement period adjustments were not recast in the 2012 consolidated financial statements as they were not deemed material.