Significant Accounting Policies (Concentration of Credit Risk) (Details)	12 Months Ended
	Dec. 31, 2012 Customers	Dec. 31, 2011	Dec. 31, 2010
Ten Largest Employer Group Premium Receivables [Member]
Significant Accounting Policies [Line Items]
Number of major customers	10
Concentration risk, percentage	14.00%	27.00%
Medicare Receivable From CMS [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	25.00%	41.00%
Ten Largest Employer Group Health Plan Services Premium Revenues [Member]
Significant Accounting Policies [Line Items]
Number of major customers	10
Concentration risk, percentage	17.00%	18.00%	17.00%
Medicare Health Plan Premium Revenues [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	27.00%	25.00%	27.00%
Los Angles County Medi-Cal Revenue to Medicad Revenue Ratio [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	44.00%
Los Angeles County Medi-Cal Revenue to Health Plan Premiums Ratio [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage	8.00%
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