Summary of Significant Accounting Policies (Concentration of Credit Risk) (Details)	12 Months Ended
	Dec. 31, 2014 Customers	Dec. 31, 2013 Customers	Dec. 31, 2012 Customers	Dec. 31, 2010
Ten Largest Employer Group Premium Receivables [Member]
Significant Accounting Policies [Line Items]
Entity-Wide Revenue, Major Customer, Number	10	10
Concentration risk, percentage	5.00%	14.00%
Medicare Receivable From CMS [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	9.00%	21.00%
MedicaidReceivablePrimarilyfromDHCS [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	84.00%	63.00%
Ten Largest Employer Group Health Plan Services Premium Revenues [Member]
Significant Accounting Policies [Line Items]
Entity-Wide Revenue, Major Customer, Number	10	10	10
Concentration risk, percentage	11.00%	16.00%	17.00%
Medicare Health Plan Premium Revenues [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	23.00%	27.00%	27.00%
MedicaidPremiumRevenues [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	36.00%	23.00%	19.00%
Los Angles County Medi-Cal Revenue to Medicaid Revenue Ratio [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	55.00%	46.00%
Los Angeles County Medi-Cal Revenue to Health Plan Premiums Ratio [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	19.00%	11.00%
Government Contracts Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	96.00%
Los Angeles County Contract with DHCS [Member]
Significant Accounting Policies [Line Items]
Current DHCS contract period			24 months	24 months