Organization and Summary of Accounting Policies - Revenues by Sources (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,743.3	$ 2,539.3	$ 2,225.1
Patent service revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,700.4	$ 2,502.1	$ 2,195.0
Patent service revenues \| Customer \| Revenue
Disaggregation of Revenue [Line Items]
Revenue by service type as a proportion of total revenues (percent)	100.00%	100.00%	100.00%
Private insurance
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,418.6	$ 1,288.0	$ 1,110.1
Private insurance \| Customer \| Revenue
Disaggregation of Revenue [Line Items]
Revenue by service type as a proportion of total revenues (percent)	52.50%	51.50%	50.60%
Government
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,128.1	$ 1,059.2	$ 949.9
Government \| Customer \| Revenue
Disaggregation of Revenue [Line Items]
Revenue by service type as a proportion of total revenues (percent)	41.80%	42.30%	43.30%
Self-pay
Disaggregation of Revenue [Line Items]
Total revenues	$ 68.1	$ 65.9	$ 61.1
Self-pay \| Customer \| Revenue
Disaggregation of Revenue [Line Items]
Revenue by service type as a proportion of total revenues (percent)	2.50%	2.60%	2.80%
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 85.6	$ 89.0	$ 73.9
Other \| Customer \| Revenue
Disaggregation of Revenue [Line Items]
Revenue by service type as a proportion of total revenues (percent)	3.20%	3.60%	3.30%
Other service revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 42.9	$ 37.2	$ 30.1
Other service revenues \| Related Party
Disaggregation of Revenue [Line Items]
Total revenues	$ 18.4	$ 15.7	$ 9.3