Accounting Policies (Details) (USD $)	1 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 month	Jun. 29, 2012
Fair Value of Financial Instruments
Minimum initial maturities of short-term investments (in months)		3
Carrying amount of long-term debt	$ 9,200,000,000	$ 9,200,000,000
Estimated fair value of long-term debt	10,800,000,000	10,800,000,000
Noncontrolling Interest
Remaining interest acquired in Generation Health (as a percent)			40.00%
Acquisition from minority interest	26,000,000
Acquisition from employee option holders			5,000,000
Aggregate acquisition cost of Remaining interest in Generation Health			$ 31,000,000