Significant Accounting Policies (State Health Programs Rate Adjustment) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Health Care Organization Revenue and Expense [Line Items]
Health plan services premiums	$ 10,377,073,000	$ 10,459,098,000	$ 9,878,687,000
Reinstated Medicaid premium tax [Member]
Health Care Organization Revenue and Expense [Line Items]
Taxes, Other	92,800,000
Reinstated Prior Year Medicaid premium taxes [Member] | Reinstated Medicaid premium tax [Member]
Health Care Organization Revenue and Expense [Line Items]
Taxes, Other	20,200,000
Medicaid Premium Revenue [Member]
Health Care Organization Revenue and Expense [Line Items]
Health plan services premiums	2,430,300,000	1,963,100,000	1,493,300,000
Medicaid Premium Revenue [Member] | Reinstated Medicaid premium tax [Member]
Health Care Organization Revenue and Expense [Line Items]
Health plan services premiums	$ 92,800,000