Segment Information - Selected Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Revenue	$ 1,788,809	$ 1,664,980
Adjusted EBITDA	261,917	214,063
Total assets	7,858,263	7,699,736	$ 7,689,631
Purchases of property, equipment, and other assets	52,517	58,885
Operating Segments \| Critical Illness Recovery Hospital
Segment Reporting Information [Line Items]
Revenue	655,880	593,926
Adjusted EBITDA	115,940	76,773
Total assets	2,608,979	2,507,265
Purchases of property, equipment, and other assets	15,941	23,658
Operating Segments \| Rehabilitation Hospital
Segment Reporting Information [Line Items]
Revenue	265,700	231,462
Adjusted EBITDA	61,400	47,216
Total assets	1,233,828	1,203,069
Purchases of property, equipment, and other assets	7,101	8,582
Operating Segments \| Outpatient Rehabilitation
Segment Reporting Information [Line Items]
Revenue	303,158	295,903
Adjusted EBITDA	24,928	30,199
Total assets	1,423,740	1,397,823
Purchases of property, equipment, and other assets	9,500	9,932
Operating Segments \| Concentra
Segment Reporting Information [Line Items]
Revenue	467,598	456,298
Adjusted EBITDA	96,142	93,748
Total assets	2,362,848	2,300,632
Purchases of property, equipment, and other assets	17,231	14,400
Other
Segment Reporting Information [Line Items]
Revenue	96,473	87,391
Adjusted EBITDA	(36,493)	(33,873)
Total assets	228,868	290,947
Purchases of property, equipment, and other assets	$ 2,744	$ 2,313