Natural Resource Partners (NRP) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Nov. 07, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'NRP	'
Entity Registrant Name	'NATURAL RESOURCE PARTNERS LP	'
Entity Central Index Key	'0001171486	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	122,278,412

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$78,126	$92,513
Accounts receivable, net of allowance for doubtful accounts	33,954	33,737
Accounts receivable - affiliates	10,547	7,666
Other	899	1,691
Total current assets	123,526	135,607
Land	24,338	24,340
Plant and equipment, net	22,839	26,435
Mineral rights, net	1,385,919	1,405,455
Intangible assets, net	58,696	66,950
Equity and other unconsolidated investments	262,414	269,338
Loan financing costs, net	9,841	11,502
Long-term contracts receivable-affiliate	50,411	51,732
Other assets	560	497
Total assets	1,938,544	1,991,856
Current liabilities:	'	'
Accounts payable and accrued liabilities	13,907	8,659
Accounts payable - affiliates	485	391
Current portion of long-term debt	80,983	80,983
Accrued incentive plan expenses - current portion	6,535	8,341
Property, franchise and other taxes payable	5,764	7,830
Accrued interest	20,376	17,184
Total current liabilities	128,050	123,388
Deferred revenue	153,931	142,586
Accrued incentive plan expenses	6,887	10,526
Other non-current liabilities	9,712	14,341
Long-term debt	1,017,498	1,084,226
Partners' capital:	'	'
Common units outstanding: (111,351,722 and 109,812,408)	613,176	606,774
General partner's interest	10,212	10,069
Non-controlling interest	-650	324
Accumulated other comprehensive loss	-272	-378
Total partners' capital	622,466	616,789
Total liabilities and partners' capital	$1,938,544	$1,991,856

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical)	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'
Common units outstanding	111,351,722	109,812,408

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues and other income:	'	'	'	'
Coal related revenues	$65,193	$62,004	$172,927	$207,236
Aggregate related revenues	2,655	3,789	9,614	9,662
Oil and gas related revenues	9,601	3,886	37,481	9,742
Equity and other unconsolidated investment income	9,685	7,238	28,865	22,168
Property taxes	3,520	4,009	10,865	11,805
Other	955	1,311	2,727	2,760
Total revenues and other income	91,609	82,237	262,479	263,373
Operating expenses:	'	'	'	'
Depreciation, depletion and amortization	18,621	17,852	49,618	50,025
Asset impairments	'	'	5,624	734
General and administrative	7,664	7,305	22,550	27,769
Property, franchise and other taxes	4,767	4,234	15,836	12,810
Oil and gas lease operating expenses	2,147	483	6,359	483
Transportation costs	354	455	1,238	1,242
Royalty payments	3,029	284	3,385	826
Total operating expenses	36,582	30,613	104,610	93,889
Income from operations	55,027	51,624	157,869	169,484
Other income (expense)	'	'	'	'
Interest expense	-18,862	-15,516	-57,759	-44,619
Interest income	8	18	75	232
Income before non-controlling interest	36,173	36,126	100,185	125,097
Non-controlling interest	'	'	'	'
Net income	36,173	36,126	100,185	125,097
Net income attributable to:	'	'	'	'
General partner	723	723	2,004	2,502
Limited partners	35,450	35,403	98,181	122,595
Basic and diluted net income per limited partner unit	$0.32	$0.32	$0.89	$1.12
Weighted average number of units outstanding	111,244	109,812	110,504	109,507
Comprehensive income	$36,543	$36,167	$100,291	$125,243

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:	'	'
Net income	$100,185	$125,097
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	49,618	50,025
Gain on reserve swap	-5,690	-8,149
Equity and other unconsolidated investment income	-28,865	-22,168
Distributions of earnings from unconsolidated investments	32,225	24,113
Non-cash interest charge, net	2,145	1,454
Gain on sale of assets	-3	-551
Asset impairment	5,624	734
Change in operating assets and liabilities:	'	'
Accounts receivable	-7,542	9,477
Other assets	750	864
Accounts payable and accrued liabilities	1,623	792
Accrued interest	3,192	-2,598
Deferred revenue	11,345	13,331
Accrued incentive plan expenses	-5,445	-80
Property, franchise and other taxes payable	-2,066	-2,826
Net cash provided by operating activities	157,096	189,515
Cash flows from investing activities:	'	'
Acquisition of plant and equipment	-207	'
Acquisition of land, coal, other mineral rights and related intangibles	-768	-38,303
Oil and gas capital expenditures	-13,267	'
Acquisition of equity interests	'	-293,077
Distributions from unconsolidated affiliates	3,633	48,833
Proceeds from sale of assets	5	559
Return on direct financing lease and contractual override	910	841
Net cash used in investing activities	-9,694	-281,147
Cash flows from financing activities:	'	'
Proceeds from loans	2,000	547,020
Repayment of loans	-69,175	-386,230
Deferred financing costs	'	-9,061
Proceeds from issuance of common units	24,826	75,000
Capital contribution by general partner	507	1,531
Costs associated with equity transactions	-601	-60
Distributions to partners	-119,346	-186,317
Net cash (used in) provided by financing activities	-161,789	41,883
Net decrease in cash and cash equivalents	-14,387	-49,749
Cash and cash equivalents at beginning of period	92,513	149,424
Cash and cash equivalents at end of period	78,126	99,675
Supplemental cash flow information:	'	'
Cash paid during the period for interest	$52,266	$45,716

Consolidated_Statements_of_Par

Consolidated Statements of Partners' Capital (Unaudited) (USD $)	Total	General Partner [Member]	Common Stock [Member]	Non-Controlling Interest [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Thousands, except Share data
Balance at Dec. 31, 2013	$616,789	$10,069	$606,774	$324	($378)
Balance, units at Dec. 31, 2013	'	'	109,812,408	'	'
Issuance of common units	24,826	'	24,826	'	'
Issuance of common units, shares	'	'	1,539,314	'	'
Capital contribution	507	507	'	'	'
Cost associated with equity transactions	-601	'	-601	'	'
Distributions	-119,346	-2,367	-116,005	-974	'
Net income	100,185	2,004	98,181	'	'
Interest rate swap from unconsolidated investments	69	'	'	'	69
Loss on interest hedge	37	'	'	'	37
Comprehensive income	100,291	'	'	'	106
Balance at Sep. 30, 2014	$622,466	$10,212	$613,176	($650)	($272)
Balance, units at Sep. 30, 2014	'	'	111,351,722	'	'

Basis_of_Presentation_and_Orga

Basis of Presentation and Organization	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation and Organization	'
	1. Basis of Presentation and Organization
	The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the nine months ended September 30, 2014 are not necessarily indicative of the results that may be expected for future periods.
	You should refer to the information contained in the footnotes included in Natural Resource Partners L.P.’s 2013 Annual Report on Form 10-K in connection with the reading of these unaudited interim consolidated financial statements.
	Natural Resource Partners L.P. (the “Partnership”) engages principally in the business of owning, managing and leasing a diversified portfolio of mineral properties in the United States, including interests in coal, an equity investment in trona and soda ash, oil and gas, construction aggregates, frac sand and other natural resources. The Partnership’s coal reserves are located in the three major U.S. coal-producing regions: Appalachia, the Illinois Basin and the Western United States, as well as lignite reserves in the Gulf Coast region. The Partnership does not operate any mines, but leases its reserves to experienced mine operators under long-term leases that grant the operators the right to mine and sell its reserves in exchange for royalty payments. The Partnership also owns and manages infrastructure assets that generate additional revenues, primarily in the Illinois Basin.
	The Partnership owns various interests in oil and gas properties that are located in the Williston Basin, the Appalachian Basin, Louisiana and Oklahoma. The Partnership’s interests in the Appalachian Basin, Louisiana and Oklahoma are minerals and royalty interests, while in the Williston Basin the Partnership owns non-operated working interests. The Partnership owns aggregate reserves located in a number of states across the country, some of which are leased to third party operators who mine and sell the reserves in exchange for royalty payments. In addition, the Partnership owns a 49% interest in OCI Wyoming LLC (“OCI Wyoming”), a trona ore mining operation and soda ash refinery in the Green River Basin, Wyoming. See “Note 4. Equity and Other Investments” for more information concerning this investment.
	The general partner of the Partnership is NRP (GP) LP, a Delaware limited partnership, whose general partner is GP Natural Resource Partners LLC, a Delaware limited liability company.

Significant_Accounting_Policie

Significant Accounting Policies Update	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies Update	'
	2. Significant Accounting Policies Update
	Reclassification
	Certain reclassifications have been made to the Consolidated Statements of Comprehensive Income. Amounts relating to prior year’s coal royalties, processing fees, transportation fees, minimums recognized as revenue, override royalties and other have been reclassified into a single line item “Coal related revenues” on this year’s Consolidated Statements of Comprehensive Income. Amounts relating to prior year’s aggregates royalties, processing fees, minimums recognized as revenue, override royalties and other have been reclassified into a single line item “Aggregates related revenues” on this year’s Consolidated Statements of Comprehensive Income. The following is reclassification reconciliation:
		Three Months Ended						Nine Months Ended
		September 30, 2013						September 30, 2013
		As		As				As		As
		Reported		Reclassified				Reported		Reclassified
		Total		Coal		Aggregate		Total		Coal		Aggregate
				Related		Related				Related		Related
				Revenues		Revenues				Revenues		Revenues
		(In thousands)
		(Unaudited)
	Revenues:
	Coal royalties	$	52,305	$	52,305	$	—	$	164,957	$	164,957	$	—
	Equity and other unconsolidated investment income		7,238		—		—		22,168		—		—
	Aggregate royalties		2,566		—		2,566		5,869		—		5,869
	Processing fees		1,377		1,263		114		3,886		3,511		375
	Transportation fees		4,742		4,742		—		13,499		13,499		—
	Oil and gas royalties		3,886		—		—		9,742		—		—
	Property taxes		4,009		—		—		11,805		—		—
	Minimums recognized as revenue		998		626		372		6,425		5,613		812
	Override royalties		2,927		2,269		658		11,011		8,713		2,298
	Other		2,189		799		79		14,011		10,943		308
	Total revenues	$	82,237	$	62,004	$	3,789	$	263,373	$	207,236	$	9,662
	Recent Accounting Pronouncements
	In May 2014, the FASB amended revenue recognition topics and created a new topic relating to revenue recognition that will supersede existing guidance under U.S. GAAP. The core principle of the new guidance is to recognize revenue when promised goods or services are transferred to the customer and in an amount that reflects the consideration expected in exchange for those goods or services. To achieve this core principle, an entity should (1) identify the contract(s) with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract and (5) recognize revenue when each performance obligation is satisfied. The guidance also specifies the accounting for some costs to obtain or fulfill a contract with a customer. Disclosure requirements include sufficient qualitative and quantitative information to enable financial statement users to understand the nature, amount, timing and uncertainty of revenues and cash flows arising from contracts with customers. The new topic is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The guidance allows for either full adoption or a modified retrospective adoption. The Partnership is currently evaluating the requirements to determine the impact, if any, of this new topic on its financial position, results of operations and cash flows.
	Other accounting standards that have been issued by the FASB or other standards-setting bodies are not expected to have a material impact on the Partnership’s financial position, results of operations or cash flows.

Recent_Acquisitions

Recent Acquisitions	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Recent Acquisitions	'
	3. Recent Acquisitions
	Sundance. On December 19, 2013, the Partnership completed the acquisition of non-operated working interests in oil and gas properties in the Williston Basin of North Dakota from Sundance Energy, Inc. for $29.4 million, following post-closing purchase price adjustments. The Partnership accounted for the transaction in accordance with the authoritative guidance for business combinations. During the third quarter of 2014, the Partnership finalized the determination of the fair value of the assets acquired and liabilities assumed in the acquisition, with no material adjustments. The assets acquired are included in Mineral rights in the accompanying Consolidated Balance Sheets.
	Abraxas. On August 9, 2013, the Partnership completed the acquisition of non-operated working interests in oil and gas properties in the Williston Basin of North Dakota and Montana from Abraxas Petroleum for $38.0 million, following post-closing purchase price adjustments. The Partnership accounted for the transaction in accordance with the authoritative guidance for business combinations. During the second quarter of 2014, the Partnership finalized the determination of the fair values of the assets acquired and liabilities assumed in the acquisition, with no material adjustments. The assets acquired are included in Mineral rights on the accompanying Consolidated Balance Sheets.
	Abraxas and Sundance combined revenues of $28.6 million and lease operating expenses of $6.4 million for the nine months ended September 30, 2014 are included in Oil and gas related revenues and Oil and gas lease operating expenses, respectively, in the accompanying Consolidated Statements of Comprehensive Income.

Equity_and_Other_Investments

Equity and Other Investments	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Equity and Other Investments	'
	4. Equity and Other Investments
	The following summarized results of operations were taken from the OCI Wyoming-prepared unaudited financial statements.
	Operating results:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
		(Unaudited)
	Sales	$	109,785		$	105,567		$	338,996		$	324,559
	Gross profit	$	28,487		$	20,545		$	83,210		$	63,860
	Net income	$	22,795		$	16,323		$	67,952		$	53,281
	Income allocation to NRP’s equity interests	$	11,170		$	7,951		$	33,300		$	24,113
	Less amortization of basis difference		(1,485	)		(713	)		(4,435	)		(1,945	)
	Equity and other unconsolidated investment income	$	9,685		$	7,238		$	28,865		$	22,168
	For both the three and nine months ended September 30, 2014, the Partnership derived 11% of its revenues and other income from its equity investment in OCI Wyoming. For the same periods of 2013, the Partnership derived 9% and 8%, respectively, of its revenues and other income from its equity investment in OCI Wyoming.
	The terms of the OCI Wyoming acquisition agreement included provisions for the payment of contingent consideration to Anadarko Holding Company if OCI Wyoming achieves certain earnings results in 2013, 2014 or 2015. The Partnership projected that the contingency would be $15 million at December 31, 2013.
	The Partnership’s contingent consideration consists of the following:
		September 30,
		2014
		(In thousands)
		(Unaudited)
	Contingent consideration, January 1, 2014	$	15,000
	Less: consideration paid during the period		(491	)
	Contingent consideration, end of the period		14,509
	Less: current portion of contingent consideration		(4,900	)
	Long-term contingent consideration	$	9,609
	The current portion is included in Accounts payable and accrued liabilities and the long term portion is included in Other non-current liabilities on the accompanying Consolidated Balance Sheets.
	In March 2014, Anadarko Holding Company (Anadarko) gave written notice to the Partnership that Anadarko believes the reorganization transactions that occurred at OCI Wyoming in July 2013 triggered an acceleration of the Partnership’s obligation to pay the additional contingent consideration in full and demanded immediate payment of such amount. The Partnership does not believe the reorganization transactions triggered an obligation to pay the additional contingent consideration, and the Partnership will continue to engage in discussions with Anadarko to resolve the issue. However, if Anadarko were to prevail on such claim, the Partnership would be required to pay an amount to Anadarko in excess of the $15 million contingency described above up to the net present value of $50 million (the maximum amount of the additional contingent consideration). Any such additional amount would be considered to be additional acquisition consideration and added to Equity and other unconsolidated investments.

Plant_and_Equipment

Plant and Equipment	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Plant and Equipment	'
	5. Plant and Equipment
	The Partnership’s plant and equipment consist of the following:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Work in process	$	207		$	—
	Plant and equipment at cost		55,271			55,271
	Less accumulated depreciation		(32,639	)		(28,836	)
	Net book value	$	22,839		$	26,435
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total depreciation expense on plant and equipment	$	3,803		$	4,698

Mineral_Rights

Mineral Rights	9 Months Ended
	Sep. 30, 2014
Extractive Industries [Abstract]	'
Mineral Rights	'
	6. Mineral Rights
	The Partnership’s mineral rights consist of the following:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Mineral rights	$	1,918,570		$	1,894,920
	Less accumulated depletion and amortization		(532,651	)		(489,465	)
	Net book value	$	1,385,919		$	1,405,455
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total depletion and amortization expense on mineral rights	$	43,185		$	42,671
	On April 7, 2014, one of the Partnership’s lessees, James River Coal Company, filed for protection under Chapter 11 of the U.S. Bankruptcy Code. At end of the second quarter of 2014, the net book value of the Partnership’s properties leased to James River was approximately $35 million, net of previously paid minimums. During the third quarter, certain of the leases, with a book value of $17 million net of previously paid minimums, were sold to Blackhawk Mining, which was already a lessee of the Partnership. Certain of the James River assets, some of which are subject to the Partnership’s leases, are still in bankruptcy and are in the process of being sold. If those remaining Partnership leases are rejected in the bankruptcy or if mining operations on the Partnership’s properties cease, the Partnership may determine that some or all of such properties are impaired. In the first nine months of 2014, those James River leases which remain in bankruptcy accounted for less than 1% of total revenues and other income, and for the year ended December 31, 2013, such leases represented less than 1% of total revenues and other income. The Partnership does not expect the resolution of the bankruptcy with regard to the remaining leases to have a material impact on its revenues and other income. The Partnership will continue to monitor these properties for potential impairment as the bankruptcy proceedings progress.

Intangible_Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible Assets	'
	7. Intangible Assets
	Amounts recorded as intangible assets along with the balances and accumulated amortization are reflected in the table below:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Contract intangibles	$	83,700		$	89,421
	Less accumulated amortization		(25,004	)		(22,471	)
	Net book value	$	58,696		$	66,950
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total amortization expense on intangible assets	$	2,630		$	2,656
	During the second quarter of 2014, the Partnership recognized an impairment expense of $5.6 million relating to an above market contract on an aggregates property. The asset impairment expense is included in Operating costs and expenses on the accompanying Consolidated Statements of Comprehensive Income.
	The estimates of future amortization expense relating to intangible assets for the periods indicated below are based on current mining plans, which are subject to revision in future periods.
		Estimated
		Amortization
		Expense
		(In thousands)
		(Unaudited)
	Remainder of 2014	$	466
	For year ended December 31, 2015		3,513
	For year ended December 31, 2016		3,470
	For year ended December 31, 2017		3,470
	For year ended December 31, 2018		3,470

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	8. Long-Term Debt
	As used in this Note 8, references to “NRP LP” refer to Natural Resource Partners L.P. only, and not to NRP (Operating) LLC or any of Natural Resource Partners L.P.’s other subsidiaries. References to “Opco” refer to NRP (Operating) LLC and its subsidiaries. References to NRP Oil and Gas refer to NRP Oil and Gas LLC, a wholly owned subsidiary of NRP LP. NRP Finance Corporation (NRP Finance) is a wholly owned subsidiary of NRP LP and a co-issuer with NRP LP on the 9.125% senior notes.
	Long-term debt consists of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	NRP LP Debt:		(Unaudited)
	$300 million 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018, issued at 99.007%		$	297,617		$	297,170
	Opco Debt:
	$300 million floating rate revolving credit facility, due August 2016			7,000			20,000
	$200 million floating rate term loan, due January 2016			99,000			99,000
	4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2018			18,467			23,084
	8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019			107,143			128,571
	5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020			46,154			53,846
	5.31% utility local improvement obligation, with annual principal and interest payments, maturing in March 2021			1,346			1,538
	5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023			24,300			27,000
	4.73% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2023			75,000			75,000
	5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024			150,000			165,000
	8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024			45,454			50,000
	5.03% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026			175,000			175,000
	5.18% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026			50,000			50,000
	NRP Oil and Gas Debt:
	Reserve-based floating rate revolving credit facility due August 2018			2,000			—
	Total debt			1,098,481			1,165,209
	Less – current portion of long term debt			(80,983	)		(80,983	)
	Long-term debt		$	1,017,498		$	1,084,226
	NRP LP Debt
	Senior Notes. In September 2013, NRP LP, together with NRP Finance as co-issuer, issued $300 million of 9.125% senior notes at an offering price of 99.007% of par value. Net proceeds after expenses related to the issuance of the senior notes of approximately $289.0 million were used to repay all of the outstanding borrowings under Opco’s revolving credit facility and $91.0 million of Opco’s term loan. The senior notes call for semi-annual interest payments on April 1 and October 1 of each year. The notes will mature on October 1, 2018.
	The indenture for the senior notes contains covenants that, among other things, limit the ability of NRP LP and certain of its subsidiaries to incur or guarantee additional indebtedness. Under the indenture, NRP LP and certain of its subsidiaries generally are not permitted to incur additional indebtedness unless, on a consolidated basis, the fixed charge coverage ratio (as defined in the indenture) is at least 2.0 to 1.0 for the four preceding full fiscal quarters. The ability of NRP LP and certain of its subsidiaries to incur additional indebtedness is further limited in the event the amount of indebtedness of NRP LP and certain of its subsidiaries that is senior to NRP LP’s unsecured indebtedness exceeds certain thresholds.
	Opco Debt
	Senior Notes. Opco made principal payments of $56.0 million on its senior notes during the nine months ended September 30, 2014. The Opco senior note purchase agreement contains covenants requiring Opco to:
		•		Maintain a ratio of consolidated indebtedness to consolidated EBITDDA (as defined in the note purchase agreement) of no more than 4.0 to 1.0 for the four most recent quarters;
		•		not permit debt secured by certain liens and debt of subsidiaries to exceed 10% of consolidated net tangible assets (as defined in the note purchase agreement); and
		•		maintain the ratio of consolidated EBITDDA to consolidated fixed charges (consisting of consolidated interest expense and consolidated operating lease expense) at not less than 3.5 to 1.0.
	The 8.38% and 8.92% senior notes also provide that in the event that Opco’s leverage ratio exceeds 3.75 to 1.00 at the end of any fiscal quarter, then in addition to all other interest accruing on these notes, additional interest in the amount of 2.00% per annum shall accrue on the notes for the two succeeding quarters and for as long thereafter as the leverage ratio remains above 3.75 to 1.00.
	Revolving Credit Facility. The weighted average interest rates for the debt outstanding under Opco’s revolving credit facility for the nine months ended September 30, 2014 and year ended December 31, 2013 were 1.96% and 2.23%, respectively. Opco incurs a commitment fee on the undrawn portion of the revolving credit facility at rates ranging from 0.18% to 0.40% per annum. The facility includes an accordion feature whereby Opco may request its lenders to increase their aggregate commitment to a maximum of $500 million on the same terms. At September 30, 2014 Opco had $7 million drawn under the credit facility.
	Opco’s revolving credit facility contains covenants requiring Opco to maintain:
		•		a ratio of consolidated indebtedness to consolidated EBITDDA (as defined in the credit agreement) not to exceed 4.0 to 1.0 and,
		•		a ratio of consolidated EBITDDA to consolidated fixed charges (consisting of consolidated interest expense and consolidated lease operating expense) of not less than 3.5 to 1.0 for the four most recent quarters.
	Term Loan Facility. During 2013, Opco issued $200 million in term debt. The weighted average interest rates for the debt outstanding under the term loan for the nine months ended September 30, 2014 and the year ended December 31, 2013 were 2.23% and 2.43%, respectively. Opco repaid $101 million in principal under the term loan during the third quarter of 2013. Repayment terms call for the remaining outstanding balance of $99 million to be paid in January 2016. The debt is unsecured but guaranteed by the subsidiaries of Opco.
	Opco’s term loan contains covenants requiring Opco to maintain:
		•		a ratio of consolidated indebtedness to consolidated EBITDDA (as defined in the credit agreement) not to exceed 4.0 to 1.0 and,
		•		a ratio of consolidated EBITDDA to consolidated fixed charges (consisting of consolidated interest expense and consolidated lease operating expense) of not less than 3.5 to 1.0 for the four most recent quarters.
	NRP Oil and Gas Debt
	Revolving Credit Facility. In August 2013, NRP Oil and Gas entered into a 5-year, $100 million senior secured, reserve-based revolving credit facility in order to fund capital expenditure requirements related to the development of non-operated working interests in oil and gas assets. The credit facility had a borrowing base of $20.0 million as of September 30, 2014 and is secured by a first priority lien and security interest in substantially all of the assets of NRP Oil and Gas. At September 30, 2014, there was $2.0 million outstanding under the credit facility. The weighted average interest rate for the debt outstanding under the credit facility for the nine months ended September 30, 2014 was 1.90%.
	Indebtedness under the NRP Oil and Gas credit facility bears interest, at the option of NRP Oil and Gas, at either:
		•		the higher of (i) the prime rate as announced by the agent bank; (ii) the federal funds rate plus 0.50%; or (iii) LIBOR plus 1%, in each case plus an applicable margin ranging from 0.50% to 1.50%; or
		•		a rate equal to LIBOR, plus an applicable margin ranging from 1.75% to 2.75%.
	NRP Oil and Gas will incur a commitment fee on the unused portion of the borrowing base under the credit facility at a rate ranging from 0.375% to 0.50% per annum.
	The NRP Oil and Gas credit facility contains certain covenants, which, among other things, require the maintenance of:
		•		a total leverage ratio (defined as the ratio of the total debt of NRP Oil and Gas to its EBITDAX) of not more than 3.5 to 1.0; and
		•		a minimum current ratio of 1.0 to 1.0.
	Consolidated Principal Payments
	The consolidated principal payments due as of September 30, 2014 are set forth below:
			NRP LP			Opco							NRP
													Oil & Gas
			Senior Notes			Senior Notes			Credit Facility		Term Loan		Credit Facility		Total
			(In thousands)
			(Unaudited)
	2014		$	—		$	24,808		$	—	$	—	$	—	$	24,808
	2015			—			80,983			—		—		—		80,983
	2016			—			80,983			7,000		99,000		—		186,983
	2017			—			80,983			—		—		—		80,983
2018			300,000	(1)		80,983			—		—		2,000		382,983
Thereafter			—			344,124			—		—		—		344,124
		$	300,000		$	692,864		$	7,000	$	99,000	$	2,000	$	1,100,864
(1)	The 9.125% senior notes due 2018 were issued at a discount and as of September 30, 2014 were carried at $297.6 million.
NRP LP, Opco and NRP Oil and Gas were in compliance with all terms under their long-term debt as of September 30, 2014.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value	'
	9. Fair Value
	The Partnership’s financial instruments consist of cash and cash equivalents, accounts receivable, accounts payable and long-term debt. The carrying amount of the Partnership’s financial instruments included in accounts receivable and accounts payable in the accompanying Consolidated Balance Sheets approximates their fair value due to their short-term nature except for the Accounts receivable – affiliates relating to the Sugar Camp override that includes both current and long-term portions. The Partnership’s cash and cash equivalents include money market accounts and are considered a Level 1 measurement. The fair market value and carrying value of the contractual override and long-term senior notes are as follows:
		Fair Value As Of				Carrying Value As Of
		September 30,		December 31,		September 30,		December 31,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)				(Unaudited)
	Assets
	Sugar Camp override, current and long-term	$	6,534	$	6,852	$	6,227	$	6,063
	Liabilities
	Long-term debt, current and long-term	$	993,935	$	1,071,880	$	990,480	$	1,046,209
	The fair value of the Sugar Camp override and long-term debt is estimated by management using comparable term risk-free treasury issues with a market rate component determined by current financial instruments with similar characteristics which is a Level 3 measurement. Since the Partnership’s credit facilities and term loan are variable rate debt, their fair values approximate their carrying amounts.

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	10. Related Party Transactions
	Reimbursements to Affiliates of the Partnership’s General Partner
	The Partnership’s general partner does not receive any management fee or other compensation for its management of Natural Resource Partners L.P. However, in accordance with the partnership agreement, the general partner and its affiliates are reimbursed for expenses incurred on the Partnership’s behalf. All direct general and administrative expenses are charged to the Partnership as incurred. The Partnership also reimburses indirect general and administrative costs, including certain legal, accounting, treasury, information technology, insurance, administration of employee benefits and other corporate services incurred by our general partner and its affiliates. The Partnership had an amount payable to Quintana Minerals Corporation of $0.5 million at September 30, 2014 for services provided by Quintana to the Partnership.
	The reimbursements to affiliates of the Partnership’s general partner for services performed by Western Pocahontas Properties and Quintana Minerals Corporation are as follows:
		Three Months				Nine Months Ended
		Ended				September 30,
		September 30,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)
	Reimbursement for services	$	2,927	$	2,748	$	8,708	$	8,481
	The Partnership also leases an office building in Huntington, West Virginia from Western Pocahontas Properties and pays $0.6 million in lease payments each year through December 31, 2018.
	Cline Affiliates
	Various companies controlled by Chris Cline, including Foresight Energy, lease coal reserves from the Partnership, and the Partnership provides coal transportation services to them for a fee. Mr. Cline, both individually and through another affiliate, Adena Minerals, LLC, owns a 31% interest (unaudited) in the Partnership’s general partner, as well as 4,917,548 common units (unaudited) at September 30, 2014. At September 30, 2014, the Partnership had accounts receivable totaling $10.3 million from Cline affiliates. In addition, the overriding royalty and the lease of the loadout facility at Foresight Energy’s Sugar Camp mine are classified as contracts receivable of $50.4 million on the Partnership’s Consolidated Balance Sheets. The Partnership has received $82.7 million in minimum royalty payments that have not been recouped by Cline affiliates, of which $11.7 million was received in the current year.
	Coal related revenues from Cline affiliates were $24.9 million and $21.0 million and $63.1 million and $68.4 million, for the three and nine months ended September 30, 2014 and 2013, respectively. For the nine months ending September 30, 2013, the results included $8.1 million from a reserve swap and $3.5 million from minimums that expired on Foresight Energy’s Macoupin mine and were recognized as revenue. For the nine months ended September 30, 2014 the results included $5.7 million from a reserve swap.
	The Partnership entered into a lease agreement related to the rail loadout and associated facilities at Sugar Camp that has been accounted for as a direct financing lease. Total projected remaining payments under the lease at September 30, 2014 are $87.6 million with unearned income of $40.0 million. The net amount receivable under the lease as of September 30, 2014 was $47.6 million, of which $1.8 million is included in Accounts receivable – affiliates while the remaining is included in Long-term contracts receivable – affiliate on the accompanying Consolidated Balance Sheets.
	In a separate transaction, the Partnership acquired a contractual overriding royalty interest from a Cline affiliate that provides for payments based upon production from specific tons at the Sugar Camp operations. This overriding royalty was accounted for as a financing arrangement and is reflected as an affiliate receivable. The net amount receivable under the agreement as of September 30, 2014 was $6.2 million, of which $1.6 million is included in Accounts receivable – affiliates while the remaining is included in Long-term contracts receivable – affiliate on the accompanying Consolidated Balance Sheets.
	Quintana Capital Group GP, Ltd.
	Corbin J. Robertson, Jr. is a principal in Quintana Capital Group GP, Ltd., which controls several private equity funds focused on investments in the energy business. In connection with the formation of Quintana Capital, the Partnership adopted a formal conflicts policy that establishes the opportunities that will be pursued by the Partnership and those that will be pursued by Quintana Capital. The governance documents of Quintana Capital’s affiliated investment funds reflect the guidelines set forth in the Partnership’s conflicts policy.
	At September 30, 2014, a fund controlled by Quintana Capital owned a majority interest in Corsa Coal Corp., a coal mining company traded on the TSX Venture Exchange that is one of the Partnership’s lessees in Tennessee. Corbin J. Robertson III, one of the Partnership’s directors, is Chairman of the Board of Corsa. Revenues from Corsa are as follows:
		Three Months				Nine Months Ended
		Ended				September 30,
		September 30,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)
	Coal royalty revenues	$	655	$	1,249	$	2,218	$	3,403
	The Partnership also had accounts receivable totaling $0.2 million from Corsa at September 30, 2014.
	A fund controlled by Quintana Capital owned a significant membership interest in Taggart Global USA, LLC, including the right to nominate two members of Taggart’s 5-person board of directors. Subsequent to the end of the second quarter of 2013, Taggart was sold to Forge Group, and Quintana no longer retains an interest in Taggart or Forge. The Partnership owns and leases preparation plants to Forge, which operates the plants. The lease payments were based on the sales price for the coal that was processed through the facilities.
	Revenues from Forge for the nine months ended September 30, 2013 were $1.8 million. Subsequent to the end of the second quarter of 2013, Taggart/Forge is no longer considered a related party of the Partnership.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	11. Commitments and Contingencies
	Legal
	The Partnership is involved, from time to time, in various legal proceedings arising in the ordinary course of business. While the ultimate results of these proceedings cannot be predicted with certainty, Partnership management believes these claims will not have a material effect on the Partnership’s financial position, liquidity or operations.
	Environmental Compliance
	The operations conducted on the Partnership’s properties are subject to environmental laws and regulations adopted by various governmental authorities in the jurisdictions in which these operations are conducted. As owner of surface interests in some properties, the Partnership may be liable for certain environmental conditions occurring at the surface properties. The terms of substantially all of the Partnership’s leases require the lessee to comply with all applicable laws and regulations, including environmental laws and regulations. Lessees post reclamation bonds assuring that reclamation will be completed as required by the relevant permit, and substantially all of the leases require the lessee to indemnify the Partnership against, among other things, environmental liabilities. Some of these indemnifications survive the termination of the lease. The Partnership has neither incurred, nor is aware of, any material environmental charges imposed on it related to its properties as of September 30, 2014. The Partnership is not associated with any environmental contamination that may require remediation costs.

Major_Lessees

Major Lessees	9 Months Ended
	Sep. 30, 2014
Risks and Uncertainties [Abstract]	'
Major Lessees	'
	12. Major Lessees
	Revenues from lessees that exceeded ten percent of total revenues and other income for the periods are presented below:
		Three Months Ended										Nine Months Ended
		September 30,										September 30,
		2014					2013					2014					2013
		(Dollars in thousands)
		(Unaudited)
		Revenues		Percent			Revenues		Percent			Revenues		Percent			Revenues		Percent
	The Cline Group	$	24,863		27	%	$	21,046		26	%	$	63,116		24	%	$	68,359		26	%
	Alpha Natural Resources	$	14,406		16	%	$	12,937		16	%	$	38,857		15	%	$	41,844		16	%
	In the first nine months of 2014, the Partnership derived over 39% of its total revenues and other income from the two companies listed above. The Partnership has a significant concentration of revenues with Cline and Alpha, although in most cases, with the exception of the Williamson mine, the exposure is spread out over a number of different mining operations and leases. Foresight Energy’s Williamson mine was responsible for approximately 16% and 12%, respectively, of the Partnership’s total revenues and other income for the three and nine months ended September 30, 2014.

Incentive_Plans

Incentive Plans	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Incentive Plans	'
	13. Incentive Plans
	GP Natural Resource Partners LLC adopted the Natural Resource Partners Long-Term Incentive Plan (the “Long-Term Incentive Plan”) for directors of GP Natural Resource Partners LLC and employees of its affiliates who perform services for the Partnership. The Compensation, Nominating and Governance (“CNG”) Committee of GP Natural Resource Partners LLC’s board of directors administers the Long-Term Incentive Plan. Subject to the rules of the exchange upon which the common units are listed at the time, the board of directors and the CNG Committee of the board of directors have the right to alter or amend the Long-Term Incentive Plan or any part of the Long-Term Incentive Plan from time to time. Except upon the occurrence of unusual or nonrecurring events, no change in any outstanding grant may be made that would materially reduce the benefit intended to be made available to a participant without the consent of the participant.
	Under the plan a grantee will receive the market value of a common unit in cash upon vesting. Market value is defined as the average closing price over the last 20 trading days prior to the vesting date. The CNG Committee may make grants under the Long-Term Incentive Plan to employees and directors containing such terms as it determines, including the vesting period. Outstanding grants vest upon a change in control of the Partnership, the general partner, or GP Natural Resource Partners LLC. If a grantee’s employment or membership on the board of directors terminates for any reason, outstanding grants will be automatically forfeited unless and to the extent the CNG Committee provides otherwise.
	A summary of activity in the outstanding grants during 2014 is as follows:
		(Unaudited)
	Outstanding grants at January 1, 2014		1,012,984
	Grants during the year		313,699
	Grants vested and paid during the year		(285,500	)
	Forfeitures during the year		(28,460	)
	Outstanding grants at September 30, 2014		1,012,723
	Grants typically vest at the end of a four-year period and are paid in cash upon vesting. The liability fluctuates with the market value of the Partnership units and because of changes in estimated fair value determined each quarter using the Black-Scholes option valuation model. Risk free interest rates and volatility are reset at each calculation based on current rates corresponding to the remaining vesting term for each outstanding grant and ranged from 0.12% to 1.06% and 28.80% to 29.92%, respectively at September 30, 2014. The Partnership’s average distribution rate of 7.4% and historical forfeiture rate of 5.2% were used in the calculation at September 30, 2014. The Partnership recorded expenses related to its plan to be reimbursed to its general partner of $1.1 million and $0.6 million for the three months ended September 30, 2014 and 2013, respectively, and for the nine months ended September 30, 2014 and 2013 the Partnership recorded expense of $1.5 million and $7.5 million, respectively. In connection with the Long-Term Incentive Plan, payments are typically made during the first quarter of the year. Payments of $6.5 million and $7.0 million were made during the nine month period ended September 30, 2014 and 2013, respectively.
	In connection with the phantom unit awards, the CNG Committee also granted tandem Distribution Equivalent Rights, or DERs, which entitle the holders to receive distributions equal to the distributions paid on the Partnership’s common units. The DERs are payable in cash upon vesting but may be subject to forfeiture if the grantee ceases employment prior to vesting.
	The unaccrued cost, associated with the unvested outstanding grants and related DERs at September 30, 2014 was $7.7 million.

Shelf_Registration_Statements_

Shelf Registration Statements and "At-the-Market" Program	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Shelf Registration Statements and "At-the-Market" Program	'
	14. Shelf Registration Statements and “At-the-Market” Program
	On April 24, 2012, the Partnership filed an automatically effective shelf registration statement on Form S-3 with the SEC that is available for registered offerings of common units and debt securities.
	On August 15, 2012, the Partnership filed a shelf registration statement on Form S-3 that registered all of the common units held by Adena Minerals. This shelf registration statement was declared effective by the SEC on September 21, 2012. Following the effectiveness of this registration statement, Adena distributed 15,181,716 common units to its shareholders, and the Partnership subsequently filed prospectus supplements to register the resale of these common units by those shareholders. The shelf registration statement filed in August 2012 also registered up to $500 million in equity securities that may be issued by the Partnership. On November 12, 2013, the Partnership filed a prospectus supplement and entered into an Equity Distribution Agreement relating to the offer and sale from time to time of common units having an aggregate offering price of $75 million through one or more managers acting as sales agents at prices to be agreed upon at the time of sale. Under the terms of the Equity Distribution Agreement, the Partnership may also sell common units from time to time to any manager as principal for its own account at a price to be agreed upon at the time of sale. Any sale of common units to any manager as principal would be pursuant to the terms of a separate terms agreement between the Partnership and such manager. Sales of common units in this “at-the-market” (“ATM”) program are made pursuant to the shelf registration statement declared effective in September 2012. For the nine months ended September 30, 2014 the Partnership sold 1,539,314 common units for an average price of $16.13 for gross proceeds of $24.8 million. In addition, the Partnership paid the ATM program manager a fee of up to 2% of the gross proceeds from the sale of common units under the ATM program.
	On April 12, 2013, the Partnership filed a resale shelf registration statement on Form S-3 to register the 3,784,572 common units issued in the January 2013 private placement related to funding of the OCI Wyoming acquisition. This shelf registration statement was declared effective by the SEC in May 2013. A portion of the common units issued in the private placement were issued, directly and indirectly, to certain of the Partnership’s affiliates, including Corbin J. Robertson, Jr. and Christopher Cline.

Distributions

Distributions	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Distributions	'
	15. Distributions
	On August 14, 2014, the Partnership paid a quarterly distribution $0.35 per unit to all holders of common units on August 5, 2014.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	16. Subsequent Events
	The following represents material events that have occurred subsequent to September 30, 2014 through the time of the Partnership’s filing of this Quarterly Report on Form 10-Q with the Securities and Exchange Commission:
	Distributions
	On October 20, 2014, the Partnership declared a distribution of $0.35 per unit to be paid on November 14, 2014 to holders of common units on November 5, 2014.
	Distributions Received From Unconsolidated Equity and Other Investments
	Subsequent to September 30, 2014, the Partnership received $10.8 million in cash distributions from its equity investment in OCI Wyoming.
	Kaiser-Francis Acquisition
	On October 5, 2014, the Partnership entered into a definitive agreement to acquire non-operated working interests in oil and gas assets located in the Bakken/Three Forks play from an affiliate of Kaiser-Francis Oil Company for $340 million, subject to customary purchase price adjustments. Upon entering into the agreement, the Partnership paid a deposit of $25 million. The assets include approximately 5,700 net acres in the Sanish Field in Mountrail County, North Dakota and include an estimated average working interest of 15% in approximately 200 wells that are producing or in various stages of development in addition to the opportunity to participate in future development locations. The assets are all held by production and are operated by Whiting Petroleum Corporation. The acquisition will have an effective date of October 1, 2014 and is expected to close in mid-November 2014, subject to the satisfaction of customary closing conditions.
	VantaCore Acquisition
	On October 1, 2014, the Partnership completed its acquisition of VantaCore Partners LP (“VantaCore”), a privately held limited partnership specializing in the construction materials industry, for $205 million in cash and common units, subject to customary post-closing purchase price adjustments. Headquartered in Philadelphia, Pennsylvania, VantaCore operates three hard rock quarries, six sand and gravel plants, two asphalt plants and a marine terminal. VantaCore’s current operations are located in Pennsylvania, West Virginia, Tennessee, Kentucky and Louisiana.
	In order to fund the VantaCore acquisition, the Partnership borrowed $169 million under Opco’s revolving credit facility and issued approximately 2.4 million common units to certain of the sellers. The closing price of the Partnership’s common units on the date of issuance was $13.02 per unit. The Partnership’s general partner’s capital contribution to maintain its 2% general partner interest in the Partnership was approximately $0.6 million.
	Equity Offering
	On October 10, 2014 the Partnership sold 8.5 million common units in an underwritten public offering registered under the Securities Act of 1933, as amended, at a public offering price of $12.02 per common unit. In connection with the offering, the Partnership granted the underwriters a 30-day option to purchase up to 1,275,000 additional common units. The Partnership intends to use the net proceeds of approximately $100.4 million from this offering, including its general partner’s proportionate capital contribution, to fund a portion of the purchase price of the Kaiser-Francis acquisition. The Partnership’s general partner’s capital contribution to maintain its 2% general partner interest in the Partnership was approximately $2.1 million.
	Senior Notes
	On October 17, 2014 the Partnership and NRP Finance Corporation (the “Issuers”) sold an additional $125 million aggregate principal amount of their 9.125% senior notes due 2018 in a private offering. The notes were issued pursuant to an indenture, dated September 18, 2013, among the Issuers and Wells Fargo Bank, National Association, as trustee. The notes constitute the same series of securities as the existing $300 million 9.125% senior notes due October 2018 issued in September 2013.
	In the offering, $105 million in aggregate principal amount of the notes were sold in a private placement to the initial purchasers thereof to be offered and sold to qualified institutional buyers pursuant to Rule 144A under the Securities Act, and to persons outside the United States pursuant to Regulation S under the Securities Act. The remaining $20 million in aggregate principal amount of the notes were sold in a separate private placement to Cline Trust Company, LLC, a Delaware limited liability company. The members of Cline Trust Company, LLC are four trusts of which the beneficiaries are the children of Christopher Cline. Donald R. Holcomb, one of the members of the Board of Directors of GP Natural Resource Partners LLC, is a manager of Cline Trust Company, LLC and the trustee of each of the four trusts that are members of Cline Trust Company, LLC.

Significant_Accounting_Policie1

Significant Accounting Policies Update (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Reclassification	'
	Reclassification
	Certain reclassifications have been made to the Consolidated Statements of Comprehensive Income. Amounts relating to prior year’s coal royalties, processing fees, transportation fees, minimums recognized as revenue, override royalties and other have been reclassified into a single line item “Coal related revenues” on this year’s Consolidated Statements of Comprehensive Income. Amounts relating to prior year’s aggregates royalties, processing fees, minimums recognized as revenue, override royalties and other have been reclassified into a single line item “Aggregates related revenues” on this year’s Consolidated Statements of Comprehensive Income. The following is reclassification reconciliation:
		Three Months Ended						Nine Months Ended
		September 30, 2013						September 30, 2013
		As		As				As		As
		Reported		Reclassified				Reported		Reclassified
		Total		Coal		Aggregate		Total		Coal		Aggregate
				Related		Related				Related		Related
				Revenues		Revenues				Revenues		Revenues
		(In thousands)
		(Unaudited)
	Revenues:
	Coal royalties	$	52,305	$	52,305	$	—	$	164,957	$	164,957	$	—
	Equity and other unconsolidated investment income		7,238		—		—		22,168		—		—
	Aggregate royalties		2,566		—		2,566		5,869		—		5,869
	Processing fees		1,377		1,263		114		3,886		3,511		375
	Transportation fees		4,742		4,742		—		13,499		13,499		—
	Oil and gas royalties		3,886		—		—		9,742		—		—
	Property taxes		4,009		—		—		11,805		—		—
	Minimums recognized as revenue		998		626		372		6,425		5,613		812
	Override royalties		2,927		2,269		658		11,011		8,713		2,298
	Other		2,189		799		79		14,011		10,943		308
	Total revenues	$	82,237	$	62,004	$	3,789	$	263,373	$	207,236	$	9,662
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In May 2014, the FASB amended revenue recognition topics and created a new topic relating to revenue recognition that will supersede existing guidance under U.S. GAAP. The core principle of the new guidance is to recognize revenue when promised goods or services are transferred to the customer and in an amount that reflects the consideration expected in exchange for those goods or services. To achieve this core principle, an entity should (1) identify the contract(s) with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract and (5) recognize revenue when each performance obligation is satisfied. The guidance also specifies the accounting for some costs to obtain or fulfill a contract with a customer. Disclosure requirements include sufficient qualitative and quantitative information to enable financial statement users to understand the nature, amount, timing and uncertainty of revenues and cash flows arising from contracts with customers. The new topic is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The guidance allows for either full adoption or a modified retrospective adoption. The Partnership is currently evaluating the requirements to determine the impact, if any, of this new topic on its financial position, results of operations and cash flows.
	Other accounting standards that have been issued by the FASB or other standards-setting bodies are not expected to have a material impact on the Partnership’s financial position, results of operations or cash flows.

Significant_Accounting_Policie2

Significant Accounting Policies Update (Tables)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Summary of Reclassification Reconciliation	'
	The following is reclassification reconciliation:
		Three Months Ended						Nine Months Ended
		September 30, 2013						September 30, 2013
		As		As				As		As
		Reported		Reclassified				Reported		Reclassified
		Total		Coal		Aggregate		Total		Coal		Aggregate
				Related		Related				Related		Related
				Revenues		Revenues				Revenues		Revenues
		(In thousands)
		(Unaudited)
	Revenues:
	Coal royalties	$	52,305	$	52,305	$	—	$	164,957	$	164,957	$	—
	Equity and other unconsolidated investment income		7,238		—		—		22,168		—		—
	Aggregate royalties		2,566		—		2,566		5,869		—		5,869
	Processing fees		1,377		1,263		114		3,886		3,511		375
	Transportation fees		4,742		4,742		—		13,499		13,499		—
	Oil and gas royalties		3,886		—		—		9,742		—		—
	Property taxes		4,009		—		—		11,805		—		—
	Minimums recognized as revenue		998		626		372		6,425		5,613		812
	Override royalties		2,927		2,269		658		11,011		8,713		2,298
	Other		2,189		799		79		14,011		10,943		308
	Total revenues	$	82,237	$	62,004	$	3,789	$	263,373	$	207,236	$	9,662

Equity_and_Other_Investments_T

Equity and Other Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Schedule of Summarized Results of Operations	'
	The following summarized results of operations were taken from the OCI Wyoming-prepared unaudited financial statements.
	Operating results:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
		(Unaudited)
	Sales	$	109,785		$	105,567		$	338,996		$	324,559
	Gross profit	$	28,487		$	20,545		$	83,210		$	63,860
	Net income	$	22,795		$	16,323		$	67,952		$	53,281
	Income allocation to NRP’s equity interests	$	11,170		$	7,951		$	33,300		$	24,113
	Less amortization of basis difference		(1,485	)		(713	)		(4,435	)		(1,945	)
	Equity and other unconsolidated investment income	$	9,685		$	7,238		$	28,865		$	22,168
Summary of OCI Contingent Consideration	'
	The Partnership’s contingent consideration consists of the following:
		September 30,
		2014
		(In thousands)
		(Unaudited)
	Contingent consideration, January 1, 2014	$	15,000
	Less: consideration paid during the period		(491	)
	Contingent consideration, end of the period		14,509
	Less: current portion of contingent consideration		(4,900	)
	Long-term contingent consideration	$	9,609

Plant_and_Equipment_Tables

Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Plant and Equipment	'
	The Partnership’s plant and equipment consist of the following:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Work in process	$	207		$	—
	Plant and equipment at cost		55,271			55,271
	Less accumulated depreciation		(32,639	)		(28,836	)
	Net book value	$	22,839		$	26,435
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total depreciation expense on plant and equipment	$	3,803		$	4,698

Mineral_Rights_Tables

Mineral Rights (Tables)	9 Months Ended
	Sep. 30, 2014
Extractive Industries [Abstract]	'
Mineral Rights	'
	The Partnership’s mineral rights consist of the following:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Mineral rights	$	1,918,570		$	1,894,920
	Less accumulated depletion and amortization		(532,651	)		(489,465	)
	Net book value	$	1,385,919		$	1,405,455
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total depletion and amortization expense on mineral rights	$	43,185		$	42,671

Intangible_Assets_Tables

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible Assets	'
	Amounts recorded as intangible assets along with the balances and accumulated amortization are reflected in the table below:
		September 30,			December 31,
		2014			2013
		(In thousands)
		(Unaudited)
	Contract intangibles	$	83,700		$	89,421
	Less accumulated amortization		(25,004	)		(22,471	)
	Net book value	$	58,696		$	66,950
		Nine Months Ended
		September 30,
		2014			2013
		(In thousands)
		(Unaudited)
	Total amortization expense on intangible assets	$	2,630		$	2,656
Estimated Amortization Expense	'
	The estimates of future amortization expense relating to intangible assets for the periods indicated below are based on current mining plans, which are subject to revision in future periods.
		Estimated
		Amortization
		Expense
		(In thousands)
		(Unaudited)
	Remainder of 2014	$	466
	For year ended December 31, 2015		3,513
	For year ended December 31, 2016		3,470
	For year ended December 31, 2017		3,470
	For year ended December 31, 2018		3,470

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-term debt consists of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	NRP LP Debt:		(Unaudited)
	$300 million 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018, issued at 99.007%		$	297,617		$	297,170
	Opco Debt:
	$300 million floating rate revolving credit facility, due August 2016			7,000			20,000
	$200 million floating rate term loan, due January 2016			99,000			99,000
	4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2018			18,467			23,084
	8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019			107,143			128,571
	5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020			46,154			53,846
	5.31% utility local improvement obligation, with annual principal and interest payments, maturing in March 2021			1,346			1,538
	5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023			24,300			27,000
	4.73% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2023			75,000			75,000
	5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024			150,000			165,000
	8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024			45,454			50,000
	5.03% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026			175,000			175,000
	5.18% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026			50,000			50,000
	NRP Oil and Gas Debt:
	Reserve-based floating rate revolving credit facility due August 2018			2,000			—
	Total debt			1,098,481			1,165,209
	Less – current portion of long term debt			(80,983	)		(80,983	)
	Long-term debt		$	1,017,498		$	1,084,226
Principal Payments Due	'
	The consolidated principal payments due as of September 30, 2014 are set forth below:
			NRP LP			Opco							NRP
													Oil & Gas
			Senior Notes			Senior Notes			Credit Facility		Term Loan		Credit Facility		Total
			(In thousands)
			(Unaudited)
	2014		$	—		$	24,808		$	—	$	—	$	—	$	24,808
	2015			—			80,983			—		—		—		80,983
	2016			—			80,983			7,000		99,000		—		186,983
	2017			—			80,983			—		—		—		80,983
	2018			300,000	(1)		80,983			—		—		2,000		382,983
	Thereafter			—			344,124			—		—		—		344,124
			$	300,000		$	692,864		$	7,000	$	99,000	$	2,000	$	1,100,864
	(1)	The 9.125% senior notes due 2018 were issued at a discount and as of September 30, 2014 were carried at $297.6 million.

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Contractual Override, Note Receivable and Long-Term Debt	'
	The fair market value and carrying value of the contractual override and long-term senior notes are as follows:
		Fair Value As Of				Carrying Value As Of
		September 30,		December 31,		September 30,		December 31,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)				(Unaudited)
	Assets
	Sugar Camp override, current and long-term	$	6,534	$	6,852	$	6,227	$	6,063
	Liabilities
	Long-term debt, current and long-term	$	993,935	$	1,071,880	$	990,480	$	1,046,209

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2014
Summary of Reimbursements	'
	The reimbursements to affiliates of the Partnership’s general partner for services performed by Western Pocahontas Properties and Quintana Minerals Corporation are as follows:
		Three Months				Nine Months Ended
		Ended				September 30,
		September 30,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)
	Reimbursement for services	$	2,927	$	2,748	$	8,708	$	8,481
Corsa [Member]	'
Summary of Revenues from Related Party	'
	Revenues from Corsa are as follows:
		Three Months				Nine Months Ended
		Ended				September 30,
		September 30,
		2014		2013		2014		2013
		(In thousands)
		(Unaudited)
	Coal royalty revenues	$	655	$	1,249	$	2,218	$	3,403

Major_Lessees_Tables

Major Lessees (Tables)	9 Months Ended
	Sep. 30, 2014
Risks and Uncertainties [Abstract]	'
Revenues from Lessees that Exceeded Ten Percent of Total Revenues and Other Income	'
	Revenues from lessees that exceeded ten percent of total revenues and other income for the periods are presented below:
		Three Months Ended										Nine Months Ended
		September 30,										September 30,
		2014					2013					2014					2013
		(Dollars in thousands)
		(Unaudited)
		Revenues		Percent			Revenues		Percent			Revenues		Percent			Revenues		Percent
	The Cline Group	$	24,863		27	%	$	21,046		26	%	$	63,116		24	%	$	68,359		26	%
	Alpha Natural Resources	$	14,406		16	%	$	12,937		16	%	$	38,857		15	%	$	41,844		16	%

Incentive_Plans_Tables

Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Summary of Activity in Outstanding Grants	'
	A summary of activity in the outstanding grants during 2014 is as follows:
		(Unaudited)
	Outstanding grants at January 1, 2014		1,012,984
	Grants during the year		313,699
	Grants vested and paid during the year		(285,500	)
	Forfeitures during the year		(28,460	)
	Outstanding grants at September 30, 2014		1,012,723

Basis_of_Presentation_and_Orga1

Basis of Presentation and Organization - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2014
	Coal_Reserves
Collaborative Arrangements Non collaborative Arrangements And Business Acquisitions Transactions [Line Items]	'
Number of coal producing regions	3
OCI Wyoming [Member]	'
Collaborative Arrangements Non collaborative Arrangements And Business Acquisitions Transactions [Line Items]	'
Percentage of partnership interest owned	49.00%

Significant_Accounting_Policie3

Significant Accounting Policies Update - Summary of Reclassification Reconciliation (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues:	'	'	'	'
Coal royalties	$24,900	$21,000	$63,100	$68,400
Equity and other unconsolidated investment income	9,685	7,238	28,865	22,168
Oil and gas royalties	9,601	3,886	37,481	9,742
Property taxes	3,520	4,009	10,865	11,805
Minimums recognized as revenue	'	'	'	3,500
Other	955	1,311	2,727	2,760
Total revenues and other income	91,609	82,237	262,479	263,373
Scenario, Previously Reported [Member]	'	'	'	'
Revenues:	'	'	'	'
Coal royalties	'	52,305	'	164,957
Equity and other unconsolidated investment income	'	7,238	'	22,168
Aggregate royalties	'	2,566	'	5,869
Processing fees	'	1,377	'	3,886
Transportation fees	'	4,742	'	13,499
Oil and gas royalties	'	3,886	'	9,742
Property taxes	'	4,009	'	11,805
Minimums recognized as revenue	'	998	'	6,425
Override royalties	'	2,927	'	11,011
Other	'	2,189	'	14,011
Total revenues and other income	'	82,237	'	263,373
Reclassified as Coal Related Revenue [Member]	'	'	'	'
Revenues:	'	'	'	'
Coal royalties	'	52,305	'	164,957
Processing fees	'	1,263	'	3,511
Transportation fees	'	4,742	'	13,499
Minimums recognized as revenue	'	626	'	5,613
Override royalties	'	2,269	'	8,713
Other	'	799	'	10,943
Total revenues and other income	'	62,004	'	207,236
Reclassified as Aggregate Related Revenue [Member]	'	'	'	'
Revenues:	'	'	'	'
Aggregate royalties	'	2,566	'	5,869
Processing fees	'	114	'	375
Minimums recognized as revenue	'	372	'	812
Override royalties	'	658	'	2,298
Other	'	79	'	308
Total revenues and other income	'	$3,789	'	$9,662

Recent_Acquisitions_Additional

Recent Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition [Line Items]	'	'	'	'
Lease operating expenses	$2,147,000	$483,000	$6,359,000	$483,000
Sundance Energy Inc [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Purchase price allocation for assets acquired	29,400,000	'	29,400,000	'
Abraxas Petroleum [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Purchase price allocation for assets acquired	38,000,000	'	38,000,000	'
Abraxas and Sundance [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Combined revenues	'	'	28,600,000	'
Lease operating expenses	'	'	$6,400,000	'

Equity_and_Other_Investments_S

Equity and Other Investments - Schedule of Summarized Results of Operations (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of Equity Method Investments [Line Items]	'	'	'	'
Net income	$36,173	$36,126	$100,185	$125,097
Equity and other unconsolidated investment income	9,685	7,238	28,865	22,168
OCI LP and OCI Co [Member]	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'
Sales	109,785	105,567	338,996	324,559
Gross profit	28,487	20,545	83,210	63,860
Net income	22,795	16,323	67,952	53,281
Income allocation to NRP's equity interests	11,170	7,951	33,300	24,113
Less amortization of basis difference	-1,485	-713	-4,435	-1,945
Equity and other unconsolidated investment income	$9,685	$7,238	$28,865	$22,168

Equity_and_Other_Investments_A

Equity and Other Investments - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Contingent consideration accrued	15	'	$15	'	'
Maximum amount of additional contingent consideration	50	'	50	'	'
OCI Wyoming [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Revenue and other income from equity investment	11.00%	9.00%	11.00%	8.00%	'
Contingent consideration, description	'	'	'The terms of the OCI Wyoming acquisition agreement included provisions for the payment of contingent consideration to Anadarko Holding Company if OCI Wyoming achieves certain earnings results in 2013, 2014 or 2015.	'	'
Contingent consideration accrued	'	'	'	'	$15

Equity_and_Other_Investments_S1

Equity and Other Investments - Summary of OCI Contingent Consideration (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Equity Method Investments and Joint Ventures [Abstract]	'	'
Contingent consideration, January 1, 2014	$14,509	$15,000
Less: consideration paid during the period	-491	'
Contingent consideration, end of the period	14,509	15,000
Less: current portion of contingent consideration	-4,900	'
Long-term contingent consideration	$9,609	'

Plant_and_Equipment_Plant_and_

Plant and Equipment - Plant and Equipment (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'	'	'
Work in process	$207	'	'
Plant and equipment at cost	55,271	'	55,271
Less accumulated depreciation	-32,639	'	-28,836
Net book value	22,839	'	26,435
Total depreciation expense on plant and equipment	$3,803	$4,698	'

Mineral_Rights_Mineral_Rights_

Mineral Rights - Mineral Rights (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Extractive Industries [Abstract]	'	'	'
Mineral rights	$1,918,570	'	$1,894,920
Less accumulated depletion and amortization	-532,651	'	-489,465
Net book value	1,385,919	'	1,405,455
Total depletion and amortization expense on mineral rights	$43,185	$42,671	'

Mineral_Rights_Additional_Info

Mineral Rights - Additional Information (Detail) (USD $)	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014
In Millions, unless otherwise specified	James River Coal Company [Member]	James River Coal Company [Member]	James River Coal Company [Member]	Blackhawk Mining [Member]
		Sales Revenue, Net [Member]	Sales Revenue, Net [Member]
Property Subject to or Available for Operating Lease [Line Items]	'	'	'	'
Book value of properties leased, net	$35	'	'	$17
Total revenue and other income, percentage	'	1.00%	1.00%	'

Intangible_Assets_Intangible_A

Intangible Assets - Intangible Assets (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'
Contract intangibles	$83,700	'	$89,421
Less accumulated amortization	-25,004	'	-22,471
Net book value	58,696	'	66,950
Total amortization expense on intangible assets	$2,630	$2,656	'

Intangible_Assets_Additional_I

Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
Disclosure Intangible Assets [Abstract]	'	'	'
Asset impairment expenses	$5,600	$5,624	$734

Intangible_Assets_Estimated_Am

Intangible Assets - Estimated Amortization Expense (Detail) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
Remainder of 2014	$466
For year ended December 31, 2015	3,513
For year ended December 31, 2016	3,470
For year ended December 31, 2017	3,470
For year ended December 31, 2018	$3,470

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)

9 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Aug. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Term Loan [Member]

Term Loan [Member]

NRP LP [Member]

NRP LP [Member]

NRP LP [Member]

NRP LP [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

Opco [Member]

NRP Oil And Gas [Member]

NRP Oil And Gas [Member]

NRP Oil And Gas [Member]

NRP Oil And Gas [Member]

NRP Oil And Gas [Member]

Maximum [Member]

Minimum [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

$300 million floating rate revolving credit facility, due August 2016 [Member]

$300 million floating rate revolving credit facility, due August 2016 [Member]

Term Loan [Member]

Maximum [Member]

Minimum [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Maximum [Member]

Minimum [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rate of Senior Notes due

9.13%

'

'

'

9.13%

9.13%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Floating rate revolving credit facility

'

'

'

'

'

$300,000,000

'

'

'

'

'

'

$300,000,000

'

'

'

'

'

'

$20,000,000

'

'

Senior Note issue percentage

'

'

'

'

'

99.01%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repayment of principal amount

'

'

101,000,000

'

'

'

'

'

289,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Term Loan

69,175,000

386,230,000

'

'

'

'

'

'

91,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed charge coverage ratio

'

'

'

'

'

'

2

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal payments on its senior notes

'

'

'

'

'

'

'

'

'

56,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Ratio of consolidated indebtedness to consolidated EBITDDA

'

'

'

'

'

'

'

'

'

4

4

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

Ratio of consolidated EBITDDA to consolidated fixed charges

'

'

'

'

'

'

'

'

'

3.5

3.5

'

'

'

'

'

'

'

'

'

'

'

Additional interest accrue

'

'

'

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

Partnership leverage ratio

'

'

'

'

'

'

'

'

'

3.75

'

'

'

'

'

'

'

'

'

'

'

'

Commitment fee on the unused portion of the borrowing base under the credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.40%

0.18%

'

'

'

0.50%

0.38%

Commitment fee on the undrawn portion of the revolving credit facility rates

'

'

'

'

'

'

'

'

'

'

'

'

'

'0.18% to 0.40%

'

'

'

'0.375% to 0.50%

'

'

'

'

Maximum increase in aggregate commitment

'

'

'

'

'

'

'

'

'

'

500,000,000

'

'

'

'

'

'

'

'

'

'

'

Weighted average interest rate

'

'

'

'

'

'

'

'

'

'

1.96%

2.23%

'

'

'

'

'

'

'

'

'

'

Amount drawn under the line of credit facility

'

'

99,000,000

'

'

'

'

'

'

'

7,000,000

'

'

'

'

'

'

'

'

2,000,000

'

'

Weighted average interest rate for the debt outstanding

1.90%

'

2.23%

2.43%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount received from debt issuance

'

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Leverage ratio, maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4

'

'

3.5

'

'

'

'

Minimum interest coverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.5

'

'

'

'

'

'

'

Term of credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

Senior secured revolving credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$100,000,000

'

'

'

Debt Instrument, Interest Rate Terms

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'The higher of (i) the prime rate as announced by the agent bank; (ii) the federal funds rate plus 0.50%; or (iii) LIBOR plus 1%, in each case plus an applicable margin ranging from 0.50% to 1.50%; or a rate equal to LIBOR, plus an applicable margin ranging from 1.75% to 2.75%

'

'

'

'

Current ratio, minimum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

LongTerm_Debt_LongTerm_Debt_De

Long-Term Debt - Long-Term Debt (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Proforma Debt Instrument [Line Items]	'	'
Total debt	$1,098,481	$1,165,209
Less - current portion of long term debt	-80,983	-80,983
Long-term debt	1,017,498	1,084,226
NRP LP [Member] | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	297,617	297,170
Opco [Member] | $300 million floating rate revolving credit facility, due August 2016 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	7,000	20,000
Opco [Member] | $200 million floating rate term loan, due January 2016 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	99,000	99,000
Opco [Member] | 4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2018 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	18,467	23,084
Opco [Member] | 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	107,143	128,571
Opco [Member] | 5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	46,154	53,846
Opco [Member] | 5.31% utility local improvement obligation, with annual principal and interest payments, maturing in March 2021 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Utility local improvement development fund	1,346	1,538
Opco [Member] | 5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	24,300	27,000
Opco [Member] | 4.73% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2023 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	75,000	75,000
Opco [Member] | 5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	150,000	165,000
Opco [Member] | 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]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	45,454	50,000
Opco [Member] | 5.03% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	175,000	175,000
Opco [Member] | 5.18% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	50,000	50,000
NRP Oil And Gas [Member] | Reserve-based floating rate revolving credit facility due August 2018 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Total debt	$2,000	'

LongTerm_Debt_LongTerm_Debt_Pa

Long-Term Debt - Long-Term Debt (Parenthetical) (Detail) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Millions, unless otherwise specified
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	9.13%	'
NRP LP [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	9.13%	9.13%
Senior Note issue percentage	'	99.01%
Floating rate revolving credit facility	'	$300
9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018 [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Senior Notes, Face amount	'	300
Rate of Senior Notes due	'	9.13%
9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018 [Member] | NRP LP [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Senior Notes, Face amount	300	'
Rate of Senior Notes due	9.13%	'
Senior Note issue percentage	99.01%	'
$300 million floating rate revolving credit facility, due August 2016 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Floating rate revolving credit facility	300	'
$200 million floating rate term loan, due January 2016 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Floating rate revolving credit facility	200	'
4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2018 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	4.91%	'
8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	8.38%	'
5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.05%	'
5.31% utility local improvement obligation, with annual principal and interest payments, maturing in March 2021 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.31%	'
5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.55%	'
4.73% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2023 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	4.73%	'
5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.82%	'
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] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	8.92%	'
5.03% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.03%	'
5.18% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026 [Member] | Opco [Member]	'	'
Proforma Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	5.18%	'

LongTerm_Debt_Principal_Paymen

Long-Term Debt - Principal Payments Due (Detail) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'
2014	$24,808
2015	80,983
2016	186,983
2017	80,983
2018	382,983
Thereafter	344,124
Principal Payments	1,100,864
NRP LP [Member] | Senior Notes [Member]	'
Debt Instrument [Line Items]	'
2014	0
2015	0
2016	0
2017	0
2018	300,000	[1]
Thereafter	0
Principal Payments	300,000
Opco [Member] | Senior Notes [Member]	'
Debt Instrument [Line Items]	'
2014	24,808
2015	80,983
2016	80,983
2017	80,983
2018	80,983
Thereafter	344,124
Principal Payments	692,864
Opco [Member] | Revolving Credit Facility [Member]	'
Debt Instrument [Line Items]	'
2014	0
2015	0
2016	7,000
2017	0
2018	0
Thereafter	0
Principal Payments	7,000
Opco [Member] | Term Loan [Member]	'
Debt Instrument [Line Items]	'
2014	0
2015	0
2016	99,000
2017	0
2018	0
Thereafter	0
Principal Payments	99,000
NRP Oil And Gas [Member] | Revolving Credit Facility [Member]	'
Debt Instrument [Line Items]	'
2014	0
2015	0
2016	0
2017	0
2018	2,000
Thereafter	0
Principal Payments	$2,000
[1]	The 9.125% senior notes due 2018 were issued at a discount and as of September 30, 2014 were carried at $297.6 million.

LongTerm_Debt_Principal_Paymen1

Long-Term Debt - Principal Payments Due (Parenthetical) (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Rate of Senior Notes due	9.13%	'
Senior notes, Carrying value	$1,098,481	$1,165,209
Senior Notes [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior notes, Carrying value	$297,600	'

Fair_Value_Contractual_Overrid

Fair Value - Contractual Override, Note Receivable and Long-Term Debt (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Fair Value of Sugar Camp override, current and long-term	$6,534	$6,852
Fair Value of Long-term debt, current and long-term	993,935	1,071,880
Carrying Value of Sugar Camp override, current and long-term	6,227	6,063
Carrying Value of Long-term debt, current and long-term	$990,480	$1,046,209

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Related Party Transaction [Line Items]	'	'	'	'	'
Lease expenses	'	'	$600,000	'	'
Accounts receivable	6,227,000	'	6,227,000	'	6,063,000
Coal related revenues from Cline affiliates	24,900,000	21,000,000	63,100,000	68,400,000	'
Reserve swap recognized as revenue	'	'	5,700,000	8,100,000	'
Expired minimums recognized as revenue	'	'	'	3,500,000	'
Accounts receivable	10,547,000	'	10,547,000	'	7,666,000
Revenues from affiliates	'	'	1,800,000	'	'
Quintana Minerals [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Amount payable to related parties	500,000	'	500,000	'	'
Corsa [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Coal related revenues from Cline affiliates	655,000	1,249,000	2,218,000	3,403,000	'
Accounts receivable	200,000	'	200,000	'	'
Cline Affiliates [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Rate of interest in the partnerships general partner	'	'	31.00%	'	'
Related party transaction number of units hold by the related party in partnerships' general partner	'	'	4,917,548	'	'
Accounts receivable	10,300,000	'	10,300,000	'	'
Contracts receivable	50,400,000	'	50,400,000	'	'
Unrecouped minimum royalty payments	'	'	82,700,000	'	'
Proceeds from royalty payments in current year	'	'	11,700,000	'	'
Net amount receivable	6,200,000	'	6,200,000	'	'
Accounts receivable	1,600,000	'	1,600,000	'	'
Sugar Camp [Member]	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Aggregate payments remaining under the lease	87,600,000	'	87,600,000	'	'
Unearned income	40,000,000	'	40,000,000	'	'
Net amount receivable	47,600,000	'	47,600,000	'	'
Accounts receivable	$1,800,000	'	$1,800,000	'	'

Related_Party_Transactions_Sum

Related Party Transactions - Summary of Reimbursements (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Related Party Transactions [Abstract]	'	'	'	'
Reimbursement for services	$2,927	$2,748	$8,708	$8,481

Related_Party_Transactions_Sum1

Related Party Transactions - Summary of Revenues from Related Party (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Related Party Transaction [Line Items]	'	'	'	'
Coal royalty revenues	$24,900	$21,000	$63,100	$68,400
Corsa [Member]	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'
Coal royalty revenues	$655	$1,249	$2,218	$3,403

Major_Lessees_Revenues_from_Le

Major Lessees - Revenues from Lessees that Exceeded Ten Percent of Total Revenues and Other Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
The Cline Group [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Revenues	$24,863	$21,046	$63,116	$68,359
Percent	27.00%	26.00%	24.00%	26.00%
Alpha Natural Resources [Member]	'	'	'	'
Operating Leased Assets [Line Items]	'	'	'	'
Revenues	$14,406	$12,937	$38,857	$41,844
Percent	16.00%	16.00%	15.00%	16.00%

Major_Lessees_Additional_Infor

Major Lessees - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Operating Leased Assets [Line Items]	'	'
Minimum Percentage of revenues and other income derived from major two leases	'	39.00%
Williamson [Member]	'	'
Operating Leased Assets [Line Items]	'	'
Percentage of revenues and other income received from major lessee excluding reserve swap	16.00%	12.00%

Incentive_Plans_Additional_Inf

Incentive Plans - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Market value of common units under the incentive plan	'	'	'Average closing price over the last 20 trading days prior to the vesting date.	'
Vesting period of Grants in years	'	'	'4 years	'
Risk free interest rate	'	'	0.12%	'
Risk free interest rate	'	'	1.06%	'
Volatility rate	'	'	28.80%	'
Volatility rate	'	'	29.92%	'
Partnership's historical distribution rate	7.40%	'	7.40%	'
Partnership's historical forfeiture rate	5.20%	'	5.20%	'
Expenses related to Incentive Plan to be reimbursed to general partner	'	'	$601,000	$60,000
Payments made in connection with Long-Term Incentive Plan	'	'	6,500,000	7,000,000
Unaccrued cost associated with outstanding grants and related DERs	7,700,000	'	7,700,000	'
General Partner [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expenses related to Incentive Plan to be reimbursed to general partner	$1,100,000	$600,000	$1,500,000	$7,500,000

Incentive_Plans_Summary_of_Act

Incentive Plans - Summary of Activity in Outstanding Grants (Detail)	9 Months Ended
	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Outstanding grants at the beginning of the period	1,012,984
Grants during the year	313,699
Grants vested and paid during the year	-285,500
Forfeitures during the year	-28,460
Outstanding grants at September 30, 2014	1,012,723

Shelf_Registration_Statements_1

Shelf Registration Statements and "At-the-Market" Program - Additional Information (Detail) (Shelf Registration Statement [Member], USD $)	0 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 12, 2013	Aug. 15, 2012	Sep. 30, 2014	Apr. 12, 2013	Aug. 15, 2012
Distribution Made to Limited Liability Company (LLC) Member [Line Items]	'	'	'	'	'
Common units distributed	'	'	'	'	15,181,716
Equity securities registered	'	$500	'	'	'
Aggregate offering price through sale agents	75	'	'	'	'
Sale of common units partnership	'	'	1,539,314	'	'
Common units partnership, average price	'	'	$16.13	'	'
Proceeds from sale of common partnership units	'	'	$24.80	'	'
Common units issued in private placement	'	'	'	3,784,572	'
Atm Program [Member]	'	'	'	'	'
Distribution Made to Limited Liability Company (LLC) Member [Line Items]	'	'	'	'	'
Fee paid to the manager, Percentage	2.00%	'	'	'	'

Distributions_Additional_Infor

Distributions - Additional Information (Detail) (USD $)	0 Months Ended
	Aug. 14, 2014
Equity [Abstract]	'
Quarterly distribution to holders of common units	$0.35

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)

0 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

1 Months Ended

In Millions, except Share data, unless otherwise specified

Aug. 14, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Oct. 20, 2014

Oct. 17, 2014

Oct. 10, 2014

Oct. 10, 2014

Oct. 05, 2014

Oct. 05, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 01, 2014

Oct. 17, 2014

Oct. 17, 2014

Nov. 07, 2014

Kaiser-Francis Oil Company [Member]

9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018 [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Kaiser-Francis Oil Company [Member]

Kaiser-Francis Oil Company [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

VantaCore Partners LP [Member]

Cline Trust Company, LLC [Member]

Senior Notes Due Two Zero One Eight [Member]

OCI Wyoming [Member]

acre

Wells

Hard Rock Quarries [Member]

Sand and Gravel Plants [Member]

Asphalt Plants [Member]

Marine Terminal [Member]

Revolving Credit Facility [Member]

Wells

Property

Property

Property

Property

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Distributions per unit declared

$0.35

'

'

'

$0.35

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash distributions from equity investment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10.80

Purchase price allocation for assets acquired

'

'

'

'

'

'

'

'

'

340

'

205

'

'

'

'

'

'

'

'

Land acquired

'

'

'

'

'

'

'

'

5,700

'

'

'

'

'

'

'

'

'

'

'

Estimated average working interest, Percentage

'

'

'

'

'

'

'

'

15.00%

'

'

'

'

'

'

'

'

'

'

'

Partnership agreement, deposit paid

'

'

'

'

'

'

'

'

25

'

'

'

'

'

'

'

'

'

'

'

Number of Oil and gas wells

'

'

'

'

'

'

'

'

'

200

'

'

'

'

'

'

'

'

'

'

Business acquisition, effective date

'

'

1-Oct-14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, closing date

'

'

'2014-11

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of operating properties owned by acquiree

'

'

'

'

'

'

'

'

'

'

'

'

3

6

2

1

'

'

'

'

Borrowings under revolving credit facility related to acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

169

'

'

'

Common units issued, related to acquisition

'

'

'

'

'

'

'

'

'

'

'

2.4

'

'

'

'

'

'

'

'

Closing price of the Partnership's common units

'

'

'

'

'

'

'

$12.02

'

'

'

$13.02

'

'

'

'

'

'

'

'

General partner interest in the Partnership

'

'

'

'

'

'

2.00%

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

Partnership's general partner's capital contribution

'

'

'

'

'

'

'

2.1

'

'

'

0.6

'

'

'

'

'

'

'

'

Sale of common units partnership

'

'

'

'

'

'

8,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriter 30-day common stock options

'

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

'

'

'

'

'

'

Underwriters option to purchase additional common units

'

'

'

'

'

'

'

1,275,000

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from equity offering

'

'

'

'

'

'

100.4

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount of senior notes

'

'

'

300

'

'

'

'

'

'

'

'

'

'

'

'

'

'

125

'

Rate of Senior Notes due

'

9.13%

'

9.13%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.13%

'

Aggregate principal amount of senior notes

'

'

'

'

'

$105

'

'

'

'

'

'

'

'

'

'

'

$20

'

'