Commitments And Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2013 class_actions
Commitments And Contingencies [Line Items]
Possible losses, in excess of established reserves, minimum	$ 0
Possible losses, in excess of established reserves, maximum	250.0
Affiliated Computer Services, Inc. [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment, amount	78.6
International Business Machines Corporation [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment, amount	$ 475.3
In re WellPoint, Inc. (n/k/a Anthem, Inc.) Out-of-Network UCR Rates Litigation [Member]
Commitments And Contingencies [Line Items]
Number of putative class actions consolidated into a single lawsuit		11