GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	$ 549,066	$ 530,955
Total accumulated amortization	(184,951)	(164,935)
Total intangible assets, net	364,115	366,020
Referral sources
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	509,646	482,200
Total accumulated amortization	(167,902)	(137,613)
Trademarks/names
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	38,508	47,718
Total accumulated amortization	(16,901)	(26,936)
Other amortizable intangible assets
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	912	1,037
Total accumulated amortization	$ (148)	$ (386)