NATURE OF BUSINESS AND BASIS OF PRESENTATION (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) center $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) center segment $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Business Acquisition [Line Items]
Number of centers | center	366		366
Number of reportable segments | segment			2
BRMG and NY Groups revenues	$ 51,300	$ 48,900	$ 151,500	$ 141,400
BRMG and NY Groups operating expenses	51,300	48,900	151,500	141,400
Management services provided to BRMG and NY Groups	214,700	190,600	638,300	584,000
BRMG and NY Groups accounts receivable	2,688,025		2,688,025		$ 2,433,907
BRMG and NY Groups accounts payable	1,891,867		1,891,867		1,942,455
Expenses from transactions with related party	$ 341,635	313,943	$ 1,038,647	934,757
ScriptSender LLC
Business Acquisition [Line Items]
Ownership percentage	49.00%		49.00%
Book value of RadNet joint venture interests	$ 2,800		$ 2,800
ScriptSender LLC | Equity Method Investee
Business Acquisition [Line Items]
Expenses from transactions with related party	800	$ 500	1,900	$ 1,500
Variable Interest Entity, Primary Beneficiary
Business Acquisition [Line Items]
BRMG and NY Groups accounts receivable	95,600		95,600		110,300
BRMG and NY Groups accounts payable	$ 17,300		$ 17,300		$ 14,400
Public Offering | Common Stock
Business Acquisition [Line Items]
Number of shares issued in transaction (in shares) | shares			8,711,250
Stock price (in dollars per share) | $ / shares	$ 29.75		$ 29.75
Gross proceeds			$ 259,200
Public offering expenses			$ 13,400