Organization and Summary of Accounting Policies - Schedule of Revenues by Sources (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 441.0	$ 416.8
Private insurance
Disaggregation of Revenue [Line Items]
Total revenues	$ 226.0	$ 215.3
Private insurance | Customer | Revenue
Disaggregation of Revenue [Line Items]
Service revenues as a percentage of total revenues	52.00%	52.40%
Government
Disaggregation of Revenue [Line Items]
Total revenues	$ 175.8	$ 164.9
Government | Customer | Revenue
Disaggregation of Revenue [Line Items]
Service revenues as a percentage of total revenues	40.50%	40.20%
Self-pay
Disaggregation of Revenue [Line Items]
Total revenues	$ 12.8	$ 10.8
Self-pay | Customer | Revenue
Disaggregation of Revenue [Line Items]
Service revenues as a percentage of total revenues	2.90%	2.60%
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 20.0	$ 19.8
Other | Customer | Revenue
Disaggregation of Revenue [Line Items]
Service revenues as a percentage of total revenues	4.60%	4.80%
Total patient service revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 434.6	$ 410.8
Total patient service revenues | Customer | Revenue
Disaggregation of Revenue [Line Items]
Service revenues as a percentage of total revenues	100.00%	100.00%
Optical Services
Disaggregation of Revenue [Line Items]
Total revenues	$ 0.8	$ 1.1
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 5.6	$ 4.9