Regulatory Requirements (Details) (USD $)	3 Months Ended														12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Regulatory Assets [Line Items]
Statutory-basis capital and suprluse of health plan subsidiaries	$ 188,500,000							$ 138,600,000							$ 188,500,000	$ 138,600,000
Statutory-basis net income of health plan subsidiaries															(130,500,000.0)	(158,000)	44,000
GAAP net income	4,900,000	[1],[2]	(8,900,000)	[3],[4]	120,900,000	[5],[6]	28,800,000	19,800,000	66,800,000	[7]	33,500,000	[8]	50,100,000	[9]	145,629,000	170,126,000	122,063,000
Statutory capital and surplus, regulatory requirements	487,000,000														487,000,000
Capital and surplus unavailable for payment of dividends	487,000,000														487,000,000
Restricted net assets	119,200,000														119,200,000
Subsidiaries [Member] | Department of Managed Health Care [Member]
Regulatory Assets [Line Items]
GAAP equity	1,300,000,000							1,200,000,000							1,300,000,000	1,200,000,000
GAAP net income															$ 202,300,000	$ 140,700,000	$ 122,100,000

[1] Includes $3.8 million pretax asset impairment primarily related to our assets held for sale in connection with the Cognizant Transaction and $68.3 million in pretax expenses primarily related to the Cognizant Transaction.

[2] ncludes $35.4 million amortization of deferred costs of health insurer's fee and $25.8 million in other ACA fees.

[3] Includes $31.9 million amortization of deferred costs of health insurer's fee and $26.6 million in other ACA fees.

[4] Includes $84.7 million pretax asset impairment related to our assets held for sale in connection with the Cognizant Transaction and $21.1 million in pretax expenses primarily related to the Cognizant transaction.

[5] Includes tax benefit of $72.6 million, net of adjustments, as a result of a loss on the stock of one of our subsidiaries.

[6] Includes $37.8 million amortization of deferred costs of health insurer's fee and $22.5 million in other ACA fees.

[7] Includes $32.1 million of Medicaid premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustments for periods prior to 2013.

[8] Includes a $12.9 million in pretax costs related to continuing efforts to address scale issues.

[9] Includes $42.2 million of Medicaid premium revenue as a result of Medicaid/Medi-Cal retroactive rate adjustments related to 2011 and 2012.