Debt Instrument, Number of Loans Received

No definition available.

Name:	rdnt_DebtInstrumentNumberofLoansReceived
Namespace Prefix:	rdnt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Periodic Payment, Percent

+ References

No definition available.

+ Details

Name:	rdnt_DebtInstrumentPeriodicPaymentPercent
Namespace Prefix:	rdnt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Periodic Payment Terms, Amortization Increase

+ References

No definition available.

+ Details

Name:	rdnt_DebtInstrumentPeriodicPaymentTermsAmortizationIncrease
Namespace Prefix:	rdnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Increase Borrowing Capacity

+ References

No definition available.

+ Details

Name:	rdnt_LineofCreditFacilityIncreaseBorrowingCapacity
Namespace Prefix:	rdnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of amortization of deferred charges applied against earnings during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

+ Details

Name:	us-gaap_AmortizationOfDeferredCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentPrincipal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Amount of debt discount to be amortized within one year or within the normal operating cycle, if longer.

+ References

+ Details

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

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

+ Details

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

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=rdnt_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=rdnt_FirstLienTermLoansAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=rdnt_FirstLienCreditAgreementSeventhAmendmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rdnt_BarclaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rdnt_SunTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_FirstLienTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_RestatedAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_FirstLienCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_FirstLienCreditAgreementSixthAmendmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MediumTermNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_FirstLienCreditAgreementEighthAmendmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rdnt_PaycheckProtectionProgramLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	rdnt_LeverageRatioAxis=rdnt_PricingLevelIIIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_EurodollarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	rdnt_LeverageRatioAxis=rdnt_LeverageRatioThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=rdnt_COVID19PandemicMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

CREDIT FACILITY AND NOTES PAYABLE (Details Narrative)				12 Months Ended
CREDIT FACILITY AND NOTES PAYABLE (Details Narrative)	Apr. 18, 2019 USD ($)	Aug. 31, 2018	Jul. 01, 2016	Dec. 31, 2020 USD ($) loan	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Aug. 22, 2017 USD ($)
Debt Instrument [Line Items]
Deferred financing costs, net of accumulated amortization				$ 1,800,000		$ 1,600,000
Term Loan
Debt Instrument [Line Items]
Total Carrying Value				652,704,000
FirstLienTermLoansAMember
Debt Instrument [Line Items]
Total Carrying Value				9,700,000
Amendment No. 7 First Lien Credit Agreement
Debt Instrument [Line Items]
Deferred financing costs, net of accumulated amortization	$ 700,000
Issuance costs	4,400,000
Debt instrument, unamortized discount, current	2,100,000
Amortization of deferred charges	1,600,000
Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding, amount				7,300,000
Deferred financing costs, net of accumulated amortization				$ 1,800,000
Effective interest rate				6.00%
Revolving Credit Facility \| Letter of Credit
Debt Instrument [Line Items]
Letters of credit outstanding, amount				$ 0
Barclays \| Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, borrowings available				$ 187,700,000
Barclays \| Revolving Credit Facility \| Letter of Credit
Debt Instrument [Line Items]
Commitment fee percentage				0.25%
Unused capacity, commitment fee percentage				0.50%
SunTrust \| Term Loan
Debt Instrument [Line Items]
Periodic payment, principal					$ 750,000
Debt periodic payment, percent of total amount					5.00%
Debt periodic payment, amortization increase					$ 375,000
SunTrust \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Credit facilities available				$ 30,000,000.0
First Lien Term Loans \| Term Loan
Debt Instrument [Line Items]
Total Carrying Value				601,329,000
Discount on term loans				9,699,000		$ 13,579,000
First Lien Term Loans \| Barclays \| Term Loan
Debt Instrument [Line Items]
Periodic payment, principal				9,700,000
SunTrust Term Loan Agreement collateralized by NJIN's tangible and intangible assets \| Term Loan
Debt Instrument [Line Items]
Total Carrying Value				51,375,000
SunTrust Term Loan Agreement collateralized by NJIN's tangible and intangible assets \| SunTrust \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Credit facilities available				30,000,000.0
First Lien Credit Agreement \| Barclays \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Total credit facilities outstanding				0
Credit facilities available				195,000,000.0
First Lien Credit Agreement \| SunTrust \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Total credit facilities outstanding				0
Amendment No. 6 First Lien Credit Agreement \| Medium-term Notes
Debt Instrument [Line Items]
Total credit facilities outstanding							$ 100,000,000.0
Amendment No. 6 First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Line of credit facility, increase borrowing capacity	$ 20,000,000.0
First Lien Credit Agreement Eighth Amendment \| Barclays \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Credit facilities available				195,000,000.0
Line of credit facility, increase borrowing capacity				57,500,000
Issuance costs				$ 700,000
Paycheck Protection Program Loans
Debt Instrument [Line Items]
Interest rate, stated percentage				1.00%
Pricing Level III \| SunTrust Term Loan Agreement collateralized by NJIN's tangible and intangible assets \| Revolving Credit Facility
Debt Instrument [Line Items]
Commitment fee percentage		2.00%
Unused capacity, commitment fee percentage		0.35%
Eurodollar \| Amendment No. 6 First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Effective interest rate				1.00%
Eurodollar \| >3.50x but ≤ 4.00x \| First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Basis spread on variable rate			3.50%
Eurodollar \| >3.50x but ≤ 4.00x \| Amendment No. 6 First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Basis spread on variable rate				3.75%
Eurodollar \| Pricing Level III \| SunTrust Term Loan Agreement collateralized by NJIN's tangible and intangible assets \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%		0.22%
Base Rate \| Amendment No. 6 First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Effective interest rate				3.25%
Base Rate \| >3.50x but ≤ 4.00x \| First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%
Base Rate \| >3.50x but ≤ 4.00x \| Amendment No. 6 First Lien Credit Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Basis spread on variable rate				2.75%
Base Rate \| Pricing Level III \| SunTrust Term Loan Agreement collateralized by NJIN's tangible and intangible assets \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
C O V I D19 Pandemic \| Paycheck Protection Program Loans
Debt Instrument [Line Items]
PPP loans, maturity term				2 years
Number of PPP loans received \| loan				4