SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Goodwill And Indefinite lived Intangibles, Long-lived assets, Leases, And Uninsured risks (Details) - USD ($)		12 Months Ended
	Oct. 01, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Goodwill		$ 907,663,000	$ 710,663,000	$ 679,463,000
Indefinite lived intangible assets		18,500,000	13,000,000.0
Loss on impairment	$ 0
Loss on impairment	$ 0	0	1,275,000	3,949,000
Lease abandonment charges		8,600,000	2,500,000	5,100,000
Workers' compensation liability, current		7,000,000.0	5,600,000
Medical malpractice deductible per incidence		10,000
Blue Shield | Minimum
Property, Plant and Equipment [Line Items]
Stop loss policy claim amount		250,000
Blue Shield | Maximum
Property, Plant and Equipment [Line Items]
Stop loss policy claim amount		1,000,000.0
Reinsurance Policy, Type [Axis]: Health Insurance Member
Property, Plant and Equipment [Line Items]
Self-insurance accrual		9,900,000	7,800,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Impairment of long lived asset		$ 1,900,000	$ 700,000	$ 2,500,000
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]		Gain (Loss) on Termination of Lease	Gain (Loss) on Termination of Lease	Gain (Loss) on Termination of Lease
Impairment loss		$ 6,700,000	$ 1,800,000	$ 2,700,000