Name:	nrc_DebtInstrumentCovenantExceptionFixedChargeCoverageRatioDividendThreshold
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The maximum cash flow leverage ratio the borrower is allowable to maintain under a debt instrument agreement.

No definition available.

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Represents maximum costs associated with building renovation that may be excluded from the fixed charge coverage ratio.

No definition available.

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Balance Type:	debit
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The minimum fixed charge coverage ratio the borrower is required to maintain under a debt instrument agreement.

No definition available.

Name:	nrc_DebtInstrumentCovenantMinimumFixedChargeCoverageRatio
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Data Type:	xbrli:pureItemType
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Represents the variable interest rate calculated at a point in time.

No definition available.

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Namespace Prefix:	nrc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

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

No definition available.

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Data Type:	dtr-types:percentItemType
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Face (par) amount of debt instrument at time of issuance.

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Name:	us-gaap_DebtInstrumentFaceAmount
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Contractual interest rate for funds borrowed, under the debt agreement.

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-Name Accounting Standards Codification
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Amount of the required periodic payments including both interest and principal payments.

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Amount of the required periodic payments applied to principal.

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Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

No definition available.

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Indicates type of variable interest rate on debt instrument.

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Data Type:	enum2:enumerationSetItemType
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Period Type:	duration

Average amount borrowed under the credit facility during the period.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The effective interest rate during the reporting period.

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Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
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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.

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-Topic 210
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Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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

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-Topic 470
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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

No definition available.

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The carrying value as of the balance sheet date of the current portion 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.

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Name:	us-gaap_LinesOfCreditCurrent
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Name:	us-gaap_DebtInstrumentAxis=nrc_CreditAgreementMember
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Data Type:	na
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Name:	srt_RangeAxis=srt_MaximumMember
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Data Type:	na
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Name:	us-gaap_LongtermDebtTypeAxis=nrc_TermLoanMember
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Data Type:	na
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Name:	us-gaap_CreditFacilityAxis=us-gaap_DelayedDrawTermLoanMember
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Data Type:	na
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Name:	us-gaap_DebtInstrumentAxis=nrc_LineOfCreditAndDelayedDrawTermLoanMember
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