Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue	$ 489,638	$ 473,964	$ 1,435,151	$ 1,397,341
Operating Segments | Total occupational health center revenue
Disaggregation of Revenue [Line Items]
Revenue	463,061	448,440	1,355,373	1,321,331
Operating Segments | Onsite health clinics
Disaggregation of Revenue [Line Items]
Revenue	15,593	15,005	46,989	44,255
Operating Segments | Other
Disaggregation of Revenue [Line Items]
Revenue	10,984	10,519	32,789	31,755
Workers’ compensation
Disaggregation of Revenue [Line Items]
Revenue	298,681	285,939	866,952	832,833
Employer services
Disaggregation of Revenue [Line Items]
Revenue	154,809	153,473	458,849	458,810
Consumer health
Disaggregation of Revenue [Line Items]
Revenue	7,332	7,162	23,327	23,150
Other occupational health center revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 2,239	$ 1,866	$ 6,245	$ 6,538