GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	$ 549,066		$ 549,066
Total accumulated amortization	(193,388)		(184,951)
Total intangible assets, net	355,678		364,115
Amortization expense for intangible assets	8,500	$ 7,500
Referral sources
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	509,646		509,646
Total accumulated amortization	(175,645)		(167,902)
Trademarks/names
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	38,508		38,508
Total accumulated amortization	(17,548)		(16,901)
Other amortizable intangible assets
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	912		912
Total accumulated amortization	$ (195)		$ (148)