5. GOODWILL AND OTHER INTANGIBLE ASSETS (Details - Schedule of Goodwill) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Goodwill, beginning balance	$ 239,553	$ 239,408
Goodwill allocated to assets held for sale		(1,126)
Goodwill transferred to other assets	(289)
Goodwill, ending balance	256,776	239,553
Advanced Radiological Imaging [Member]
Goodwill acquired through acquisitions		1,280
Diagnostic Imaging Group, LLC [Member]
Adjustments to preliminary allocations of purchase price		(47)
Landmark Imaging [Member]
Goodwill acquired through acquisitions		$ 38
Resolution Imaging Medical Corp [Member]
Goodwill acquired through acquisitions	1,901
MRI Centers, Inc. [Member]
Goodwill acquired through acquisitions	401
Goodwill, ending balance	401
Santa Monica Imaging Group JV [Member]
Goodwill acquired through acquisitions	(1,901)
D&D Diagnostics, Inc [Member]
Goodwill acquired through acquisitions	1,519
Goodwill, ending balance	1,500
Stockton MRI, Inc [Member]
Goodwill acquired through acquisitions	3,101
Goodwill, ending balance	3,100
Hematology Oncology [Member]
Goodwill acquired through acquisitions	(110)
DIA, Inc [Member]
Goodwill acquired through acquisitions	9,185
Adjustments to preliminary allocations of purchase price	1,058
Breastlink Medical [Member]
Goodwill acquired through acquisitions	(509)
RDI, Inc. [Member]
Goodwill acquired through acquisitions	1,202
RadSite, LLC [Member]
Goodwill acquired through acquisitions	$ 1,665

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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