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Major Lessees - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Alpha Natural Resources
Operating Leased Assets [Line Items]
Non-recurring lease assignment fee	$ 6.0

X

- Definition

Revenue From Lease Assignment Fees, Nonrecurring

+ References

No definition available.

+ Details

Name:	nrp_RevenueFromLeaseAssignmentFeesNonrecurring
Namespace Prefix:	nrp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

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

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=nrp_AlphaNaturalResourcesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: