Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Long Term Acute Care
Disaggregation of Revenue [Line Items]
Total net operating revenues	$ 464,676	$ 445,123
Long Term Acute Care | Patient services revenue
Disaggregation of Revenue [Line Items]
Total net operating revenues	460,998	443,062
Long Term Acute Care | Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	240,992	236,437
Long Term Acute Care | Non-Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	220,006	206,625
Long Term Acute Care | Other revenues
Disaggregation of Revenue [Line Items]
Total net operating revenues	3,678	2,061
Inpatient Rehabilitation
Disaggregation of Revenue [Line Items]
Total net operating revenues	174,774	144,825
Inpatient Rehabilitation | Patient services revenue
Disaggregation of Revenue [Line Items]
Total net operating revenues	134,743	104,747
Inpatient Rehabilitation | Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	72,841	57,504
Inpatient Rehabilitation | Non-Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	61,902	47,243
Inpatient Rehabilitation | Other revenues
Disaggregation of Revenue [Line Items]
Total net operating revenues	40,031	40,078
Outpatient Rehabilitation
Disaggregation of Revenue [Line Items]
Total net operating revenues	257,381	250,371
Outpatient Rehabilitation | Patient services revenue
Disaggregation of Revenue [Line Items]
Total net operating revenues	227,090	220,501
Outpatient Rehabilitation | Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	38,190	36,698
Outpatient Rehabilitation | Non-Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	188,900	183,803
Outpatient Rehabilitation | Other revenues
Disaggregation of Revenue [Line Items]
Total net operating revenues	30,291	29,870
Concentra
Disaggregation of Revenue [Line Items]
Total net operating revenues	356,116	250,589
Concentra | Patient services revenue
Disaggregation of Revenue [Line Items]
Total net operating revenues	353,880	248,346
Concentra | Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	628	545
Concentra | Non-Medicare
Disaggregation of Revenue [Line Items]
Total net operating revenues	353,252	247,801
Concentra | Other revenues
Disaggregation of Revenue [Line Items]
Total net operating revenues	$ 2,236	$ 2,243