Merger Agreement and Health Plan Sale (Details Textual) (USD $) In Billions, except Per Share data, unless otherwise specified	1 Months Ended	9 Months Ended
	Oct. 31, 2012	Sep. 30, 2012
Merger Agreement and Health Plan Sale [Line Items]
Date of execution of merger agreement		Jul. 09, 2012
Date of execution of a merger agreement amendment	Oct. 02, 2012
Merger agreement, offered price per share		$ 92
Date the proposed merger was approved by the shareholders	Oct. 23, 2012
Date the plan of acquisition filed by WellPoint was approved by the Tennessee Department of Commerce and Insurance	Oct. 02, 2012
Merger agreement, approximate purchase price, gross		$ 4.9
Expected period in which consummation of the merger will ocur		fourth quarter of 2012
Virginia health plan contingent sale agreement date		Sep. 27, 2012