Segment Reporting - Assets and Cash Purchases of Property and Equipment by Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total assets	$ 6,876.7	$ 6,682.1
Total cash purchases of property and equipment	88.8	80.6	$ 57.6
Operating Segments | Surgical Facility Services
Segment Reporting Information [Line Items]
Total assets	6,347.4	6,001.1
Total cash purchases of property and equipment	87.9	74.3	55.0
Operating Segments | Ancillary Services
Segment Reporting Information [Line Items]
Total assets	36.3	41.7
Total cash purchases of property and equipment	0.8	1.1	0.5
All other
Segment Reporting Information [Line Items]
Total assets	493.0	639.3
Total cash purchases of property and equipment	$ 0.1	$ 5.2	$ 2.1