SUMMARY OF ACCOUNTING POLICIES (Details Narrative)				3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 01, 2019 USD ($)	Mar. 01, 2018 USD ($)	Feb. 01, 2018 USD ($) shares	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) joint_venture	Apr. 01, 2017	Mar. 24, 2017 USD ($)
Property, Plant and Equipment [Line Items]
Contracts receivable, factored amount								$ 20,500,000
Contracts receivable, factoring expense								440,000
Contracts receivable, factoring receivable				$ 16,600,000		$ 16,600,000
Deferred financing costs, net of accumulated amortization				1,800,000		1,800,000		1,400,000
Deferred financing costs, net, period increase						683,000
Goodwill				437,940,000		437,940,000		418,093,000
Indefinite-lived intangible assets				10,200,000		10,200,000
Impairment of intangible assets								3,900,000
Goodwill, impairment loss								3,800,000
Indefinite-lived trade names								100,000
Income tax expense				$ 2,969,000	$ 2,505,000	$ 1,740,000	$ 8,000
Effective tax rate				28.10%	27.90%	23.50%	0.80%
Total credit facilities outstanding				$ 0		$ 0
Investment at cost				30,634,000		30,634,000		30,030,000
Aggregate cost				66,240,000		66,240,000		$ 65,031,000
Number of unconsolidated joint ventures | joint_venture								14
Loss on economic interest transaction						(134,000)
Management service fees				1,800,000	$ 3,900,000	$ 3,900,000	$ 7,600,000
Minimum
Property, Plant and Equipment [Line Items]
Share-based payment award, award vesting period						3 years
Share-based payment award, expiration period						5 years
Maximum
Property, Plant and Equipment [Line Items]
Share-based payment award, award vesting period						5 years
Share-based payment award, expiration period						10 years
Medic Vision
Property, Plant and Equipment [Line Items]
Ownership percentage		14.21%								12.50%
Investment at cost		$ 200,000								$ 1,000,000
Option to purchase additional equity method investment										$ 1,400,000
Additional equity interest acquired		1.96%
Initial qwnership percentage after dilution		12.25%
Aggregate cost				$ 1,200,000		$ 1,200,000
Turner Imaging
Property, Plant and Equipment [Line Items]
Number of shares purchased (in shares) | shares			2,100,000.0
Number of shares purchased, value			$ 2,000,000
Restated Plan
Property, Plant and Equipment [Line Items]
Shares authorized (in shares) | shares				14,000,000		14,000,000
Restated Plan | Minimum
Property, Plant and Equipment [Line Items]
Share-based payment award, award vesting period						3 years
Share-based payment award, expiration period						5 years
Restated Plan | Maximum
Property, Plant and Equipment [Line Items]
Share-based payment award, award vesting period						5 years
Share-based payment award, expiration period						10 years
2016 Caps
Property, Plant and Equipment [Line Items]
Premium liability for 2016 Caps				$ 5,300,000		$ 5,300,000
2016 Caps | September 2020
Property, Plant and Equipment [Line Items]
Notional amounts				150,000,000		150,000,000
2016 Caps | October 2020
Property, Plant and Equipment [Line Items]
Notional amounts				350,000,000		350,000,000
2019 SWAPS
Property, Plant and Equipment [Line Items]
Notional amounts				500,000,000		500,000,000
2019 SWAPS | October 2023
Property, Plant and Equipment [Line Items]
Notional amounts				50,000,000		50,000,000
2019 SWAPS | October 2025
Property, Plant and Equipment [Line Items]
Notional amounts				$ 200,000,000		$ 200,000,000
Property and equipment, net | Minimum
Property, Plant and Equipment [Line Items]
PPE estimated useful lives						3 years
Property and equipment, net | Maximum
Property, Plant and Equipment [Line Items]
PPE estimated useful lives						15 years
Leasehold Improvements | Minimum
Property, Plant and Equipment [Line Items]
PPE estimated useful lives						3 years
Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
PPE estimated useful lives						15 years
2016 Caps | London Interbank Offered Rate (LIBOR)
Property, Plant and Equipment [Line Items]
Basis spread on variable rate				2.00%		2.00%
2019 SWAPS - Interest Rate Contracts | 2019 SWAPS
Property, Plant and Equipment [Line Items]
Notional amounts				$ 100,000,000		$ 100,000,000
2019 SWAPS - Interest Rate Contracts | 2019 SWAPS1
Property, Plant and Equipment [Line Items]
Notional amounts				$ 400,000,000		$ 400,000,000
2019 SWAPS - Interest Rate Contracts | London Interbank Offered Rate (LIBOR) | 2019 SWAPS
Property, Plant and Equipment [Line Items]
Basis spread on variable rate				1.96%		1.96%
2019 SWAPS - Interest Rate Contracts | London Interbank Offered Rate (LIBOR) | 2019 SWAPS1
Property, Plant and Equipment [Line Items]
Basis spread on variable rate				2.05%		2.05%
Revolving Credit Facility
Property, Plant and Equipment [Line Items]
Deferred financing costs, net of accumulated amortization				$ 1,800,000		$ 1,800,000
Total credit facilities outstanding				0		0		$ 28,000,000
RadNet | Santa Monica Imaging Group
Property, Plant and Equipment [Line Items]
Ownership percentage	35.00%								40.00%
Loss on economic interest transaction	$ 2,000
Cedars Sinai Medical Center | Santa Monica Imaging Group
Property, Plant and Equipment [Line Items]
Ownership percentage									60.00%
Additional equity interest acquired	5.00%
Investment owned, value	$ 134,000
Dignity Health | Glendale Advanced Imaging | Joint Venture | Minimum
Property, Plant and Equipment [Line Items]
Variable interest entity, ownership percentage								25.00%
Dignity Health | Glendale Advanced Imaging | Joint Venture | Maximum
Property, Plant and Equipment [Line Items]
Variable interest entity, ownership percentage								55.00%
Promissory Note
Property, Plant and Equipment [Line Items]
Convertible promissory note				0		0		$ 199,000
Promissory Note | Turner Imaging
Property, Plant and Equipment [Line Items]
Convertible promissory note	$ 143,000
US Attorney's Office For The Western District of New York
Property, Plant and Equipment [Line Items]
Loss contingency accrual liability				2,300,000		2,300,000
Pending Litigation | US Attorney's Office For The Western District of New York | Minimum
Property, Plant and Equipment [Line Items]
Loss contingency, estimate of possible loss				2,000,000		2,000,000
Pending Litigation | US Attorney's Office For The Western District of New York | Maximum
Property, Plant and Equipment [Line Items]
Loss contingency, estimate of possible loss				$ 2,500,000		$ 2,500,000