Summary of Significant Accounting Policies - Table 4 (Details)	Dec. 31, 2015	Dec. 31, 2014
Concentration Of Net Patient Service Accounts Receivable By Payor Class [Abstract]
Medicare	70.50%	72.20%
Managed care and other discount plans, including Medicare Advantage	19.70%	18.50%
Medicaid	2.90%	1.80%
Other third-party payors	4.10%	3.80%
Workers' compensation	1.90%	1.90%
Patients	0.90%	1.80%
Total	100.00%	100.00%