XML 89 R60.htm IDEA: XBRL DOCUMENT v3.3.1.900

Mineral Rights Schedule of Impairment Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Asset impairment expenses	$ 50,953	$ 626,838	$ 3,803	$ 0	$ 20,585	$ 0	$ 5,624	$ 0	$ 681,594	$ 26,209	$ 734
Oil And Gas Mineral Rights
Property, Plant and Equipment [Line Items]
Asset impairment expenses	31,900	335,700							367,576	0	0
Fair value of impaired assets	108,000								108,000
Coal Mineral Rights
Property, Plant and Equipment [Line Items]
Asset impairment expenses	8,200	247,800	$ 1,500		16,800				257,468	16,793	734
Fair value of impaired assets	400								400
Hard Mineral Royalty
Property, Plant and Equipment [Line Items]
Asset impairment expenses		$ 43,400							43,402	3,013
Fair value of impaired assets	$ 0								0
Mining Properties and Mineral Rights
Property, Plant and Equipment [Line Items]
Asset impairment expenses									$ 668,446	$ 19,806	$ 734
Aggregate Mineral Rights
Property, Plant and Equipment [Line Items]
Asset impairment expenses					$ 3,000

X

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

+ Details

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

X

- Definition

Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19190-110258

+ Details

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

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

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nrp_OilAndGasMineralRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nrp_CoalMineralRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nrp_HardMineralRoyaltyPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MiningPropertiesAndMineralRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nrp_AggregateMineralRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: