Medical Costs and Medical Costs Payable	9 Months Ended
Sep. 30, 2011
Medical Costs and Medical Costs Payable [Abstract]
Medical Costs and Medical Costs Payable	Medical Costs and Medical Costs Payable Medical costs and medical costs payable include estimates of the Company’s obligations for medical care services that have been rendered on behalf of insured consumers, but for which claims have either not yet been received or processed, and for liabilities for physician, hospital and other medical cost disputes. The Company develops estimates for medical costs incurred but not reported using an actuarial process that is consistently applied, centrally controlled and automated. The actuarial models consider factors such as time from date of service to claim receipt, claim backlogs, care provider contract rate changes, medical care consumption and other medical cost trends. The Company estimates liabilities for physician, hospital and other medical cost disputes based upon an analysis of potential outcomes, assuming a combination of litigation and settlement strategies. Each period, the Company re-examines previously established medical costs payable estimates based on actual claim submissions and other changes in facts and circumstances. As the medical costs payable estimates recorded in prior periods develop, the Company adjusts the amount of the estimates and includes the changes in estimates in medical costs in the period in which the change is identified. For the three months ended September 30, 2011, there was $90 million of net favorable medical cost development related to prior fiscal years and $110 million of net favorable medical cost development related to the first half of 2011. For the nine months ended September 30, 2011, medical costs included $650 million of net favorable medical cost development related to prior fiscal years. The favorable development in 2011 was primarily driven by continued efficiencies in claims submission, handling and processing, which results in higher completion factors, and lower than expected health system utilization levels. For the three months ended September 30, 2010, there was $80 million of net favorable medical cost development related to prior fiscal years and $150 million of net favorable medical cost development related to the first half of 2010. For the nine months ended September 30, 2010, medical costs included $660 million of net favorable medical cost development related to prior fiscal years. The favorable development for 2010 was primarily driven by lower than expected health system utilization levels and more efficient claims handling and processing.

Medical Costs and Medical Costs Payable

Medical costs and medical costs payable include estimates of the Company’s obligations for medical care services that have been rendered on behalf of insured consumers, but for which claims have either not yet been received or processed, and for liabilities for physician, hospital and other medical cost disputes. The Company develops estimates for medical costs incurred but not reported using an actuarial process that is consistently applied, centrally controlled and automated. The actuarial models consider factors such as time from date of service to claim receipt, claim backlogs, care provider contract rate changes, medical care consumption and other medical cost trends. The Company estimates liabilities for physician, hospital and other medical cost disputes based upon an analysis of potential outcomes, assuming a combination of litigation and settlement strategies. Each period, the Company re-examines previously established medical costs payable estimates based on actual claim submissions and other changes in facts and circumstances. As the medical costs payable estimates recorded in prior periods develop, the Company adjusts the amount of the estimates and includes the changes in estimates in medical costs in the period in which the change is identified.

For the three months ended September 30, 2011, there was $90 million of net favorable medical cost development related to prior fiscal years and $110 million of net favorable medical cost development related to the first half of 2011. For the nine months ended September 30, 2011, medical costs included $650 million of net favorable medical cost development related to prior fiscal years. The favorable development in 2011 was primarily driven by continued efficiencies in claims submission, handling and processing, which results in higher completion factors, and lower than expected health system utilization levels.

For the three months ended September 30, 2010, there was $80 million of net favorable medical cost development related to prior fiscal years and $150 million of net favorable medical cost development related to the first half of 2010. For the nine months ended September 30, 2010, medical costs included $660 million of net favorable medical cost development related to prior fiscal years. The favorable development for 2010 was primarily driven by lower than expected health system utilization levels and more efficient claims handling and processing.