GOODWILL AND OTHER INTANGIBLE ASSETS (Details - Schedule of Goodwill) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 441,973	$ 418,093
Goodwill disposed of through sale or transfer		(123)
Goodwill transferred to other assets		992
Goodwill, ending balance	472,879	441,973
Medical Arts Radiological Group, PC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		722
Dignity Health
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		1
West Valley Imaging Group, LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		2,490
Hudson Valley Radiology Associates
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		3,125
Kern Radiology Imaging Systems Inc.
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		10,507
Zilkha Radiology
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		2,577
Ramic Mahwah LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		231
Garden State Radiology Network LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		2,021
Nulogix, Inc.
Goodwill [Roll Forward]
Goodwill acquired through acquisitions		$ 1,337
Olney Open MRI, LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	601
MRI at Woodbridge, LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	1,833
DeepHealth, Inc.
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	23,299
AZ-Tech Radiology & Open MRI, LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	2,882
ZP Ozone Park, LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	828
ZP Elmhurst LLC
Goodwill [Roll Forward]
Goodwill acquired through acquisitions	$ 1,463