Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Provisions For Contractual Discounts And Uncompensated Care [Abstract]
Gross billings	100.00%	100.00%
Provision for contractual discounts	38.00%	36.00%
Provision for uncompensated care	33.00%	34.00%