Basis of Presentation - Table 1 (Details)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Basis of Presentation [Abstract]
Medicare	74.90%	75.20%
Medicaid	2.60%	1.30%
Workers’ compensation	0.90%	1.30%
Managed care and other discount plans, including Medicare Advantage	18.20%	18.10%
Other third-party payors	1.50%	1.60%
Patients	0.70%	1.00%
Other income	1.20%	1.50%
Total	100.00%	100.00%