Organization and Summary of Accounting Policies - Variable Interest Entities (Details) $ in Millions	Sep. 30, 2020 USD ($)	Sep. 30, 2020 surgical_facilities	Sep. 30, 2020 physician_practice	Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items]
Number of facilities included in VIE		4	3
Assets	$ 5,312.9			$ 5,018.9
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	28.2			36.2
Liabilities	$ 22.2			$ 25.2