Segment Reporting - Assets and Cash Purchases of Property and Equipment by Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets	$ 5,090.9		$ 5,018.9
Purchases of property and equipment, net	11.8	$ 11.8
Operating Segments | Surgical Facility Services
Segment Reporting Information [Line Items]
Assets	4,596.9		4,580.4
Purchases of property and equipment, net	11.0	10.9
Operating Segments | Ancillary Services
Segment Reporting Information [Line Items]
Assets	69.9		69.6
Purchases of property and equipment, net	0.1	0.1
Operating Segments | Optical Services
Segment Reporting Information [Line Items]
Assets	17.7		17.7
All Other
Segment Reporting Information [Line Items]
Assets	406.4		$ 351.2
Purchases of property and equipment, net	$ 0.7	$ 0.8