Commitments And Contingencies (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
International Business Machines Corporation [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment, amount	$ 107.4
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	94.3
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	$ 250.0
In re WellPoint, Inc. Out-of-Network UCR Rates Litigation [Member]
Commitments And Contingencies [Line Items]
Number of putative class actions consolidated into a single lawsuit	11