GOODWILL AND OTHER INTANGIBLE ASSETS, NET - Activity Related to Other Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Intangible Assets [Roll Forward]
Beginning balance	$ 74,183	$ 64,700
Additions	55,500	30,300
Reclass to amortizable intangible	0
Write-off		(4,200)
Amortization	(18,500)	(16,600)
Ending balance	111,190	74,183
Amortizable acquired names [Member]
Intangible Assets [Roll Forward]
Beginning balance	5,500	5,600
Additions	0	7,000
Reclass to amortizable intangible	6,600
Write-off		0
Amortization	(9,000)	(7,100)
Ending balance	3,100	5,500
Noncompete Agreements [Member]
Intangible Assets [Roll Forward]
Beginning balance	7,800	3,400
Additions	6,200	11,500
Reclass to amortizable intangible	0
Write-off		0
Amortization	(7,600)	(7,100)
Ending balance	6,400	7,800
Technology-Based Intangible Assets
Intangible Assets [Roll Forward]
Beginning balance	0	0
Additions	20,200	0
Reclass to amortizable intangible	0
Write-off		0
Amortization	(1,200)	0
Ending balance	19,000	0
Certificates of Need and Licenses [Member]
Intangible Assets [Roll Forward]
Beginning balance	47,000	37,600
Additions	800	11,800
Reclass to amortizable intangible	0
Write-off		0
Amortization	(700)	(2,400)
Ending balance	47,100	47,000
Unamortizable acquired names [Member]
Intangible Assets [Roll Forward]
Beginning balance	13,900	18,100
Additions	28,300	0
Reclass to amortizable intangible	(6,600)
Write-off		(4,200)
Amortization	0	0
Ending balance	$ 35,600	$ 13,900