Commitments And Contingencies (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
International Business Machines Corporation [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment initiation date	first quarter of 2010
Long-term purchase commitment, amount	$ 296,700,000
Long Term Purchase Commitment Expiration Date	Mar. 31, 2015
Affiliated Computer Services, Inc. [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment initiation date	March 31, 2009
Long-term purchase commitment, amount	157,100,000
Long Term Purchase Commitment Expiration Date	Mar. 31, 2016
Minimum [Member]
Commitments And Contingencies [Line Items]
Possible losses, in excess of established reserves, minimum	0
Maximum [Member]
Commitments And Contingencies [Line Items]
Possible losses, in excess of established reserves, maximum	350,000,000
LA City Attorney [Member]
Commitments And Contingencies [Line Items]
Amended complaint filing date	October 2010
Punitive charges requested per alleged violation of the California business and professional code	2,500
Ltigation settlement	$ 6,000,000
Litigation settlement agreement date	2013-07-10
In re WellPoint, Inc. Out-of-Network UCR Rates Litigation [Member]
Commitments And Contingencies [Line Items]
Number of putative class actions that were consolidated into a single multi-district lawsuit	11