Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 26, 2024	Jun. 30, 2024
Subsequent Event [Line Items]
Common stock, par value (in dollars per share)		$ 0.01
Select Medical Corporation | Concentra Group Holdings Parent
Subsequent Event [Line Items]
Outstanding member interest		100.00%
Subsequent Event | IPO
Subsequent Event [Line Items]
Number of shares issued in initial public offering (in shares)	22,500,000
Common stock, par value (in dollars per share)	$ 0.01
Sale of stock, price per share (in dollars per share)	$ 23.50
Proceeds from initial public offering	$ 499.7
Underwriting discounts and commissions	29.1
Net proceeds of IPO and debt financing transactions, excluding amounts repaid for debt	$ 34.7
Subsequent Event | IPO | Select Medical Corporation | Concentra Group Holdings Parent
Subsequent Event [Line Items]
Outstanding member interest	81.74%
Subsequent Event | IPO | Senior Secured Credit Facilities | Concentra Health Services, Inc. ("CHSI")
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 1,250.0
Subsequent Event | IPO | Term loan | Concentra Health Services, Inc. ("CHSI")
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 850.0
Credit spread adjustment	2.25%
Subsequent Event | IPO | Line of Credit | Concentra Health Services, Inc. ("CHSI") | Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 400.0
Credit spread adjustment	2.50%
Subsequent Event | IPO | 6.875 Senior Notes Due 2032 | Senior notes | Concentra Health Services, Inc. ("CHSI")
Subsequent Event [Line Items]
Principal outstanding	$ 650.0
Interest rate of debt (as a percent)	6.875%
Subsequent Event | IPO | Select Medical Revolving Promissory Note
Subsequent Event [Line Items]
Repayments of debt	$ 420.0
Subsequent Event | Over-Allotment Option
Subsequent Event [Line Items]
Number of shares issued in initial public offering (in shares)	750,000
Underwriting discounts and commissions	$ 1.0
Net proceeds received	$ 16.7