Contingencies and Other Matters - Legal and Regulatory Matters (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended	6 Months Ended	3 Months Ended		12 Months Ended
	Jun. 30, 2014 Pending Litigation [Member]	Mar. 31, 2013 Unfavorable Regulatory Action [Member]	Jun. 30, 2014 Unfavorable Regulatory Action [Member]	Mar. 31, 2013 Unfavorable Regulatory Action [Member] Prior Claims [Member]	Mar. 31, 2013 Unfavorable Regulatory Action [Member] Current Claims [Member]	Dec. 31, 2009 Use Of Ingenix Data [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	$ 189
Loss Contingency Accrual At Carrying Value, Net Of Tax	123
Loss Contingency Accrual, Carrying Value, Payments						10
Monitoring period			2 years
Reassessment period			2 years
Reassessment period, California			3 years
Loss Contingency Accrual, Carrying Value, Provision		77		48	29
Loss Contingency Accrual Carrying Value, Provision, After Tax		$ 51