The amount of monthly base rent payments for the operating lease of a lessee.

No definition available.

Name:	nrc_LesseeOperatingLeaseMonthlyBaseRentPayments
Namespace Prefix:	nrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Remaining lease term of operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121573735&loc=d3e41499-112717

+ Details

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

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
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- Details

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Note 10 - Leases (Details Textual) - USD ($)	1 Months Ended	12 Months Ended
Note 10 - Leases (Details Textual) - USD ($)	Feb. 28, 2021	Dec. 31, 2018	Dec. 31, 2020
Operating Leases, Rent Expense, Net, Total		$ 779,000
Subsequent Event [Member]
Lessee, Operating Lease, Monthly Base Rent Payments	$ 14,288
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)			1 year
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)			4 years 8 months 12 days