GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	$ 554,509		$ 554,519
Total accumulated amortization	(227,710)		(219,123)
Total intangible assets, net	326,799		335,396
Amortization expense for intangible assets	8,600	$ 8,500
Referral sources
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	514,388		514,388
Total accumulated amortization	(206,906)		(199,084)
Trademarks/names
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	39,136		39,136
Total accumulated amortization	(20,423)		(19,698)
Other amortizable intangible assets
Finite-Lived Intangible Assets [Line Items]
Total gross intangible assets	985		995
Total accumulated amortization	$ (381)		$ (341)