Significant Accounting Policies (Medicaid Premium Taxes) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Health Care Organization Revenue and Expense [Line Items]
Health plan services premiums	$ 2,881,345	$ 2,632,069
Medicaid Premium Revenue [Member]
Health Care Organization Revenue and Expense [Line Items]
Health plan services premiums	$ 862,000	$ 600,300