Significant Accounting Policies (Health Plan Services Revenue Recognition) (Details) (USD $)	3 Months Ended			12 Months Ended
	Sep. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Medicare and Medicaid/Medi-Cal [Member]	Dec. 31, 2012 Medicare and Medicaid/Medi-Cal [Member]	Dec. 31, 2011 Medicare and Medicaid/Medi-Cal [Member]	Dec. 31, 2013 Medicaid Premium Revenue [Member]	Dec. 31, 2012 Medicaid Premium Revenue [Member]
Health Care Organizations [Line Items]
Percentage of health plan services premiums generated under contract						50.00%	45.00%	40.00%
Medicaid Retro Rate Adjustment	$ 32,100,000	$ 42,200,000	$ 31,500,000	$ 74,300,000	$ 21,700,000
State settlement premium revenue									62,900,000
Settlement account balance, beginning										0
Settlement account payment, maximum									264,000,000
Settlement account payment, current balance									62,900,000
Receivable with imputed interest, discount									$ 4,400,000