Debt instrument additional basis spread.

No definition available.

Name:	nrp_DebtInstrumentAdditionalBasisSpread
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument additional variable interest rate.

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentAdditionalVariableInterestRate
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Asset Sales Proceeds, Required to Repay Outstanding Debt, Percent

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentAssetSalesProceedsRequiredtoRepayOutstandingDebtPercent
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Covenant, Asset Sales

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentCovenantAssetSales
Namespace Prefix:	nrp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentCovenantConsolidatedLeverageRatioMaximum
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Covenant, Debt Limit Numerator

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentCovenantDebtLimitNumerator
Namespace Prefix:	nrp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Instrument, Covenant, Dividend Payment Restriction, Percent

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentCovenantDividendPaymentRestrictionPercent
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Covenant, Maximum Leverage Ratio

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentCovenantMaximumLeverageRatio
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Discount on Debt Issuance, as a Percent

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentDiscountonDebtIssuanceasaPercent
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Fee on Redemption, Percent

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentFeeonRedemptionPercent
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument Issuance At Par Percentage

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentIssuanceAtParPercentage
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Net Redemption Premium, Percent

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentNetRedemptionPremiumPercent
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Percentage of Principal Eligible for Redemption

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentPercentageofPrincipalEligibleforRedemption
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Redemption Premium Above Par, Percentage

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentRedemptionPremiumAboveParPercentage
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument redemption price at change of control event as percentage of principal amount.

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentRedemptionPriceAtChangeOfControlEventAsPercentageOfPrincipalAmount
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument redemption price percentage of principal remaining after redemption.

+ References

No definition available.

+ Details

Name:	nrp_DebtInstrumentRedemptionPricePercentageOfPrincipalRemainingAfterRedemption
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed Charge Coverage Ratio

+ References

No definition available.

+ Details

Name:	nrp_FixedChargeCoverageRatio
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Partnership leverage ratio.

+ References

No definition available.

+ Details

Name:	nrp_PartnershipLeverageRatio
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of consolidated net tangible assets debt of subsidiaries not permitted to exceed.

+ References

No definition available.

+ Details

Name:	nrp_PercentageOfConsolidatedNetTangibleAssetsDebtOfSubsidiariesNotPermittedToExceed
Namespace Prefix:	nrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio of EBITDA to consolidated fixed charges.

+ References

No definition available.

+ Details

Name:	nrp_RatioOfEbitdaToConsolidatedFixedCharges
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio of indebtedness.

+ References

No definition available.

+ Details

Name:	nrp_RatioOfIndebtedness
Namespace Prefix:	nrp_
Data Type:	xbrli:pureItemType
Balance Type:	na
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/presentationRef
-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=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-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=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Amount of assets pledged to secure a debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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=6877327&loc=d3e13212-122682

+ Details

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

- 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

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
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

- Definition

The distribution amount per share for all classes of units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_PartnersCapitalDistributionAmountPerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

+ Details

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

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_RepaymentsOfLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=nrp_SeniorNotesdue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=nrp_SeniorNotesdue2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nrp_CinerWyomingLLCMember
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:	dei_LegalEntityAxis=nrp_NRPLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=nrp_OpcoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nrp_DebtCovenantTermsAxis=nrp_RestrictedPaymentsCovenantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nrp_DebtCovenantTermsAxis=nrp_DebtIncurrenceCovenantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nrp_DebtCovenantTermsAxis=nrp_DividendatorBelow0.45perShareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nrp_DebtCovenantTermsAxis=nrp_DividendAbove0.45perShareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Additional Information (Detail)				1 Months Ended	3 Months Ended		9 Months Ended
Debt - Additional Information (Detail)	Oct. 02, 2017 USD ($)	Apr. 03, 2017 USD ($)	Mar. 02, 2017 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 31, 2014 USD ($)	Jul. 31, 2013	Jan. 31, 2013
Debt Instrument [Line Items]
Senior Note issue percentage			98.75%
Debt issuance cost capitalized					$ 17,531,000		$ 17,531,000				$ 7,339,000
Principal balance					955,869,000		955,869,000				1,138,932,000
Discount on debt issuance (as a percent)			1.25%
Debt Instrument, Net Redemption Premium, Percent			5.813%
Redemption fee (as a percent)			1.25%
Call premium (as a percent)			4.563%
Aggregate principal amount redeemable (as a percent)			35.00%
Senior Notes due 2022
Debt Instrument [Line Items]
Principal balance					329,732,000		329,732,000				0
Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Rate of senior notes			10.50%
Senior Notes, Face Amount			$ 346,000,000
Proceeds from issuance of secured debt			$ 105,000,000
Principal remaining after redemption (as a percent)			65.00%
Purchase price (as a percent)			101.00%
Senior Notes due 2018
Debt Instrument [Line Items]
Principal balance					$ 94,362,000		$ 94,362,000				420,097,000
Senior Notes due 2018 \| Senior Notes
Debt Instrument [Line Items]
Debt redeemed		$ 90,000,000
Senior Notes, Face Amount			$ 241,000,000
Redemption price (as a percent)		104.563%
Ciner Wyoming
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)					49.00%		49.00%						49.00%	48.51%
Ciner Wyoming \| Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)					49.00%		49.00%
NRP LP
Debt Instrument [Line Items]
Rate of senior notes				9.125%
Floating rate revolving credit facility				$ 300,000,000.0								$ 125,000,000.0
Senior Note issue percentage				99.007%								99.50%
NRP LP \| 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Rate of senior notes					9.125%		9.125%
Principal balance					$ 94,362,000		$ 94,362,000				425,000,000
Senior Notes, Face Amount					$ 425,000,000		$ 425,000,000
NRP LP \| Maximum
Debt Instrument [Line Items]
Fixed charge coverage ratio					2.0		2.0
NRP LP \| Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio					1.0		1.0
Opco
Debt Instrument [Line Items]
Ratio of consolidated EBITDDA to consolidated fixed charges							3.5
Percentage of consolidated net tangible assets debt of subsidiaries not permitted to exceed							10.00%
Repayment of principal amount				$ 289,000,000
Opco \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period					5.49%	4.87%	5.22%	4.24%
Debt issuance cost capitalized					$ 6,100,000		$ 6,100,000
Commitment fee on the unused portion of the borrowing base under the credit facility (percent)							0.50%
Debt Instrument, Asset Sales Proceeds, Required to Repay Outstanding Debt, Percent							75.00%
Collateral carrying amount					$ 653,500,000		$ 653,500,000				673,000,000
Ratio of consolidated EBITDDA to consolidated fixed charges							3.5
Opco \| 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019 [Member]
Debt Instrument [Line Items]
Rate of senior notes					8.38%		8.38%
Principal balance					$ 42,669,000		$ 42,669,000				64,029,000
Opco \| 8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024 [Member]
Debt Instrument [Line Items]
Rate of senior notes					8.92%		8.92%
Principal balance					$ 31,733,000		$ 31,733,000				36,272,000
Opco \| Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Covenant, Asset Sales					300,000,000		$ 300,000,000
Debt Instrument, Asset Sales Proceeds, Required to Repay Outstanding Debt, Percent							25.00%
Principal balance					$ 446,900,000		$ 446,900,000				503,000,000
Principal payments on its senior notes							$ (56,100,000)	$ (56,000,000)
Partnership leverage ratio							3.75
Additional interest accrue					2.00%		2.00%
Opco \| Floating Rate Revolving Credit Facility Due April Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility					$ 180,000,000		$ 180,000,000
Principal balance					$ 69,000,000		$ 69,000,000				$ 210,000,000
Opco \| Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Distribution amount (in dollars per share) \| $ / shares					$ 0.45		$ 0.45
Opco \| Maximum
Debt Instrument [Line Items]
Ratio of consolidated indebtedness to consolidated EBITDDA							4.0
Opco \| Scenario, Forecast [Member] \| Floating Rate Revolving Credit Facility Due April Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility									$ 100,000,000	$ 150,000,000
Opco \| Federal Funds Rate [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)							0.50%
Opco \| London Interbank Offered Rate (LIBOR) [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)							1.00%
Opco \| London Interbank Offered Rate (LIBOR) [Member] \| Maximum \| Revolving Credit Facility Basis Spread Condition One [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)							3.50%
Opco \| London Interbank Offered Rate (LIBOR) [Member] \| Maximum \| Revolving Credit Facility Basis Spread Condition Two [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)							4.50%
Opco \| London Interbank Offered Rate (LIBOR) [Member] \| Minimum \| Revolving Credit Facility Basis Spread Condition One [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)							2.50%
Opco \| London Interbank Offered Rate (LIBOR) [Member] \| Minimum \| Revolving Credit Facility Basis Spread Condition Two [Member] \| Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)							3.50%
Debt Instrument, Redemption, Period One \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)			110.50%
Debt Instrument, Redemption, Period Two \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)			105.25%
Debt Instrument, Redemption, Period Three \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)			102.625%
Debt Instrument, Redemption, Period Four \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)			100.00%
Restricted Payments Covenant \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Consolidated leverage ratio, maximum			4.00
Distribution limit (as a percent)			50.00%
Debt Incurrence Covenant \| Senior Notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Consolidated leverage ratio, maximum			3.00
Debt covenant, maximum debt			$ 150,000,000
Dividend at or Below $0.45 per Share \| Opco \| Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Maximum leverage ratio			4.0				4.0
Dividend Above $0.45 per Share \| Opco \| Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Maximum leverage ratio							3.0
Subsequent Event \| Senior Notes due 2018 \| Senior Notes
Debt Instrument [Line Items]
Debt redeemed	$ 94,400,000
Redemption price (as a percent)	100.00%