Regulatory Requirements (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Regulatory Assets [Line Items]
Capital contributions made to subsidiary to maintain target Risk Based Capital																	$ 17,600,000
Restricted cash and cash equivalents	800,000								5,300,000								800,000	5,300,000
Assets Held-in-trust	25,500,000								20,700,000								25,500,000	20,700,000
Statutory-basis capital and suprluse of health plan subsidiaries	143,800,000								159,500,000								143,800,000	159,500,000
Statutory-basis net income of health plan subsidiaries																	44,000	4,300,000	17,600,000
GAAP net income	6,000,000	[1],[2]	18,000,000	[3]	124,600,000	[4]	(26,600,000)	[5]	60,200,000	[6]	61,800,000	[7]	58,300,000	[8]	(108,200,000)	[9]	122,063,000	72,120,000	204,243,000
Statutory capital and surplus, regulatory requirements	410,600,000																410,600,000
Capital and surplus unavailable for payment of dividends	410,600,000																410,600,000
Restricted net assets	163,000,000																163,000,000
Subsidiaries [Member] | Department of Managed Health Care [Member]
Regulatory Assets [Line Items]
GAAP equity	1,200,000,000								1,200,000,000								1,200,000,000	1,200,000,000
GAAP net income																	$ 122,100,000	$ 181,100,000	$ 146,900,000

[1] Includes a $2.2 million unfavorable adjustment to the gain on sale of discontinued operation, an $8.2 million expense related to our G&A cost reduction efforts, a $5.0 million expense related to the early termination of a medical management contract and $7.1 million of litigation-related expenses.

[2] Includes $31.5 million of premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustment related to the third quarter of 2012 and prior periods.

[3] Includes a $2.4 million unfavorable adjustment to the gain on sale of discontinued operation and a $7.2 million expense related to our G&A cost reduction efforts.

[4] Includes $119.4 million gain on sale of discontinued operation related to the sale of our Medicare PDP business to CVS Caremark. Also, includes $7.9 million of adverse development related to prior years recorded as part of health care costs, and a $10.8 million expense related to our G&A cost reduction efforts.

[5] Includes $25.0 million of adverse development related to prior periods recorded as part of health care costs, a $9.5 million expense related to our G&A cost reduction efforts and an unfavorable $0.7 million in pretax litigation reserve adjustment. Also includes a $6.5 million insurance reimbursement related to a prior legal settlement.

[6] Includes a $9.7 million expense related to our cost management initiatives and a $6.3 million benefit from litigation reserve adjustments

[7] Includes a $4.7 million expense related to our cost management initiatives and a $0.2 million benefit from litigation reserve adjustments

[8] Includes a $2.7 million expense related to our cost management initiatives, a $0.3 million benefit from litigation reserve adjustments and a $6.3 million favorable adjustment to loss on sale of Northeast health plan subsidiaries.

[9] Includes a $177.2 million expense incurred as a result of the Louisiana Supreme Court’s judgment in the AmCareco litigation, an $11.0 million expense related to our cost management initiatives and a $34.9 million favorable adjustment to loss of sale of Northeast health plan subsidiaries.