Revenue and Accounts Receivable Accounts Receivable (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	$ 127,910	$ 107,998
Less: allowance for doubtful accounts	(16,540)	(13,811)
Accounts receivable	111,370	94,187
Medicaid
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	38,068	28,534
Managed care
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	30,911	26,707
Medicare
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	34,562	32,168
Private other payors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Gross	$ 24,369	$ 20,589