Medicare Part D (Balance Sheet Accounts Associated with Medicare Part D) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Other current assets	$ 721,537	$ 583,141
Trade accounts payable and accrued expenses	(1,944,897)	(1,624,832)
Other long-term assets	1,126,637	1,082,736
Other long-term liabilities	(427,741)	(272,867)
Risk Corridor Settlement [Member]
Other current assets	1,507	1,563
Trade accounts payable and accrued expenses	(400,806)	(389,203)
Net current liability	(399,299)	(387,640)
Other long-term assets	4,349	0
Other long-term liabilities	(147,235)	0
Net long-term liability	(142,886)	0
Total net liability	(542,185)	(387,640)
CMS Subsidies [Member]
Other current assets	77,686	16,211
Trade accounts payable and accrued expenses	(420,075)	(170,231)
Net current liability	(342,389)	(154,020)
Other long-term assets	0	0
Other long-term liabilities	0	0
Net long-term liability	0	0
Total net liability	$ (342,389)	$ (154,020)