GOODWILL AND OTHER INTANGIBLE ASSETS (Details - Annual Amortization Schedule) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Finite-Lived Intangible Assets [Line Items]
Amortization year 2019	$ 2,674
Amortization year 2020	2,599
Amortization year 2021	2,538
Amortization year 2022	2,508
Amortization year 2023	2,394
Amortization year thereafter	27,880
Amortiztion total	40,593
Management Service Contracts
Finite-Lived Intangible Assets [Line Items]
Amortization year 2019	2,287
Amortization year 2020	2,287
Amortization year 2021	2,287
Amortization year 2022	2,287
Amortization year 2023	2,287
Amortization year thereafter	18,108
Amortiztion total	$ 29,543
Weighted average amortization period remaining in years	12 years 10 months 24 days
Covenant Not To Compete
Finite-Lived Intangible Assets [Line Items]
Amortization year 2019	$ 376
Amortization year 2020	301
Amortization year 2021	240
Amortization year 2022	210
Amortization year 2023	98
Amortization year thereafter	0
Amortiztion total	$ 1,225
Weighted average amortization period remaining in years	3 years 10 months 18 days
Trade Names Amortized
Finite-Lived Intangible Assets [Line Items]
Amortization year 2019	$ 11
Amortization year 2020	11
Amortization year 2021	11
Amortization year 2022	11
Amortization year 2023	9
Amortiztion total	$ 53
Weighted average amortization period remaining in years	5 years
Trade Names Indefinite Life
Finite-Lived Intangible Assets [Line Items]
Amortization year 2019	$ 0
Amortization year 2020	0
Amortization year 2021	0
Amortization year 2022	0
Amortization year 2023	0
Amortization year thereafter	9,772
Amortiztion total	$ 9,772

Weighted average amortization period remaining in years

No definition available.

Name:	rdnt_WeightedAverageAmortizationPeriodRemainingInYears
Namespace Prefix:	rdnt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rdnt_ManagementServiceContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rdnt_CovenantNotToCompeteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rdnt_TradeNamesAmortizedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rdnt_TradeNamesIndefiniteLifeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: