Net Revenues and Accounts Receivable (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	$ 300,585	$ 259,857
Less: Allowance for doubtful accounts	(10,680)	(8,777)
Net Accounts Receivable	289,905	251,080
Medicare [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	214,366	192,541
Medicaid and Local Government [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	48,183	31,259
Commercial Insurance and Other [Member]
Accounts receivable attributable to major payer sources of reimbursement
Gross Accounts Receivable	$ 38,036	$ 36,057