Net Revenues and Accounts Receivable (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	$ 303,237	$ 300,585
Less: Allowance for doubtful accounts	(11,899)	(10,680)
Net Accounts Receivable	291,338	289,905
Medicare [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	215,797	214,366
Medicaid and Local Government [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	49,731	48,183
Commercial Insurance and Other [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	$ 37,709	$ 38,036