Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,788,809	$ 1,664,980
Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	1,659,211	1,545,295
Medicare
Disaggregation of Revenue [Line Items]
Total revenue	398,754	385,482
Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	1,260,457	1,159,813
Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	129,598	119,685
Operating Segments \| Critical Illness Recovery Hospital
Disaggregation of Revenue [Line Items]
Total revenue	655,880	593,926
Operating Segments \| Critical Illness Recovery Hospital \| Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	654,927	592,688
Operating Segments \| Critical Illness Recovery Hospital \| Medicare
Disaggregation of Revenue [Line Items]
Total revenue	226,261	229,383
Operating Segments \| Critical Illness Recovery Hospital \| Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	428,666	363,305
Operating Segments \| Critical Illness Recovery Hospital \| Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	953	1,238
Operating Segments \| Rehabilitation Hospital
Disaggregation of Revenue [Line Items]
Total revenue	265,700	231,462
Operating Segments \| Rehabilitation Hospital \| Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	252,963	219,980
Operating Segments \| Rehabilitation Hospital \| Medicare
Disaggregation of Revenue [Line Items]
Total revenue	126,386	110,055
Operating Segments \| Rehabilitation Hospital \| Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	126,577	109,925
Operating Segments \| Rehabilitation Hospital \| Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	12,737	11,482
Operating Segments \| Outpatient Rehabilitation
Disaggregation of Revenue [Line Items]
Total revenue	303,158	295,903
Operating Segments \| Outpatient Rehabilitation \| Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	285,454	277,786
Operating Segments \| Outpatient Rehabilitation \| Medicare
Disaggregation of Revenue [Line Items]
Total revenue	45,841	45,801
Operating Segments \| Outpatient Rehabilitation \| Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	239,613	231,985
Operating Segments \| Outpatient Rehabilitation \| Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	17,704	18,117
Operating Segments \| Concentra
Disaggregation of Revenue [Line Items]
Total revenue	467,598	456,298
Operating Segments \| Concentra \| Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	465,867	454,841
Operating Segments \| Concentra \| Medicare
Disaggregation of Revenue [Line Items]
Total revenue	266	243
Operating Segments \| Concentra \| Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	465,601	454,598
Operating Segments \| Concentra \| Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,731	1,457
Other
Disaggregation of Revenue [Line Items]
Total revenue	96,473	87,391
Other \| Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Other \| Medicare
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Other \| Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Other \| Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 96,473	$ 87,391