Natural Resource Partners (NRP) 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares shares in Millions	3 Months Ended
	Mar. 31, 2016	May. 01, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Trading Symbol	NRP
Entity Registrant Name	NATURAL RESOURCE PARTNERS LP
Entity Central Index Key	1,171,486
Current Fiscal Year End Date	--03-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 52,097	$ 51,773
Accounts receivable, net	48,154	50,167
Accounts receivable—affiliates	7,525	6,864
Inventory	7,406	7,835
Prepaid expenses and other	3,835	4,490
Total current assets	119,017	121,129
Land	25,022	25,022
Plant and equipment, net	57,444	61,239
Mineral rights, net	1,060,829	1,094,027
Intangible assets, net	3,701	3,930
Intangible assets, net—affiliate	52,274	52,997
Equity in unconsolidated investment	258,939	261,942
Long-term contracts receivable—affiliate	45,931	47,359
Other assets	1,204	1,266
Other assets—affiliate	532	1,124
Total assets	1,624,893	1,670,035
Current liabilities:
Accounts payable	7,595	8,465
Accounts payable—affiliates	1,227	1,464
Accrued liabilities	40,004	45,735
Current portion of long-term debt, net	154,441	80,745
Total current liabilities	203,267	136,409
Deferred revenue	76,750	80,812
Deferred revenue—affiliates	81,868	82,853
Long-term debt, net	1,146,958	1,270,281
Long-term debt, net—affiliate	19,936	19,930
Other non-current liabilities	$ 5,839	$ 6,808
Commitments and contingencies
Partners’ capital:
Common unitholders’ interest (12.2 million units outstanding)	$ 96,615	$ 79,094
General partner’s interest	(249)	(606)
Accumulated other comprehensive loss	(2,697)	(2,152)
Total partners’ capital	93,669	76,336
Non-controlling interest	(3,394)	(3,394)
Total capital	90,275	72,942
Total liabilities and capital	$ 1,624,893	$ 1,670,035

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - shares shares in Millions	Mar. 31, 2016	Feb. 18, 2016	Feb. 17, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common units outstanding (in shares)	12.2	12.2	122.3	12.2

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues and other income:
Total revenues and other income	$ 80,826	$ 107,611
Gain on asset sales	21,925	2,066
Total revenues and other income	102,751	109,677
Operating expenses:
Operating and maintenance expenses	30,902	37,421
Operating and maintenance expenses—affiliates, net	3,748	3,076
Depreciation, depletion and amortization	14,021	24,554
Amortization expense—affiliates	722	838
General and administrative	3,235	2,287
General and administrative—affiliates	937	1,084
Asset impairment	2,030	0
Total operating expenses	55,595	69,260
Income from operations	47,156	40,417
Other income (expense)
Interest expense	(23,748)	(22,943)
Interest income	19	15
Other expense, net	(23,729)	(22,928)
Net income	23,427	17,489
Net income attributable to partners:
Limited partners	23,024	17,139
General partner	$ 403	$ 350
Basic and diluted net income per common unit (in dollars per share)	$ 1.88	$ 1.40
Weighted average number of common units outstanding (in shares)	12,230	12,230
Add: comprehensive loss from unconsolidated investment and other	$ (545)	$ (965)
Comprehensive income	22,882	16,524
Coal, Hard Mineral Royalty and Other
Revenues and other income:
Total revenues and other income	28,476	34,449
Coal, hard mineral royalty and other—affiliates	10,569	19,061
VantaCore
Revenues and other income:
Total revenues and other income	24,682	26,799
Oil and Gas
Revenues and other income:
Total revenues and other income	7,298	14,779
Soda Ash
Revenues and other income:
Total revenues and other income	$ 9,801	$ 12,523

Consolidated Statements of Part

Consolidated Statements of Partners' Capital - 3 months ended Mar. 31, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	General Partner	Common Unitholders	Accumulated Other Comprehensive Loss	Partners' Capital Excluding Non-Controlling Interest	Non-Controlling Interest
Balance, beginning of period at Dec. 31, 2015	$ 72,942	$ (606)	$ 79,094	$ (2,152)	$ 76,336	$ (3,394)
Balance, beginning of period (in shares) at Dec. 31, 2015			12,230
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to unitholders	(5,616)	(113)	$ (5,503)		(5,616)
Net income	23,427	403	23,024		23,427
Non-cash contributions	67	67			67
Comprehensive loss from unconsolidated investment and other	(545)			(545)	(545)
Balance, end of period at Mar. 31, 2016	$ 90,275	$ (249)	$ 96,615	$ (2,697)	$ 93,669	$ (3,394)
Balance, end of period (in shares) at Mar. 31, 2016			12,230

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 23,427	$ 17,489
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	14,021	24,554
Amortization expense—affiliates	722	838
Distributions from equity earnings from unconsolidated investments	12,250	10,903
Asset impairment	2,030	0
Gain on asset sales	(21,925)	(2,066)
Equity earnings from unconsolidated investment	(9,801)	(12,523)
Other, net	1,887	1,056
Other, net—affiliates	664	7
Change in operating assets and liabilities:
Accounts receivable	5,782	15,110
Accounts receivable—affiliates	(661)	3,643
Accounts payable	(48)	(2,642)
Accounts payable—affiliates	(237)	(14)
Accrued liabilities	(5,900)	(5,354)
Deferred revenue	(4,063)	5,845
Deferred revenue—affiliates	(985)	(738)
Other items, net	1,146	103
Other items, net—affiliates	1,119	(739)
Net cash provided by operating activities	19,428	55,472
Cash flows from investing activities:
Acquisition of mineral rights	(2,725)	(16,788)
Acquisition of plant and equipment and other	(2,221)	(1,365)
Proceeds from sale of plant and equipment and other	3	905
Proceeds from sale of oil and gas properties	32,848	3,395
Proceeds from sale of coal and hard mineral royalty properties	9,802	866
Return of long-term contract receivables—affiliate	309	1,137
Net cash provided by (used in) investing activities	38,016	(11,850)
Cash flows from financing activities:
Proceeds from loans	0	25,000
Repayments of loans	(51,166)	(41,166)
Distributions to partners	(5,616)	(43,678)
Distributions to non-controlling interest	0	(662)
Debt issue costs and other	(338)	83
Net cash used in financing activities	(57,120)	(60,423)
Net increase (decrease) in cash and cash equivalents	324	(16,801)
Cash and cash equivalents at beginning of period	51,773	50,076
Cash and cash equivalents at end of period	52,097	33,275
Supplemental cash flow information:
Cash paid during the period for interest	13,812	14,344
Plant, equipment and mineral rights funded with accounts payable or accrued liabilities	$ 811	$ 3,761

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Nature of Business Natural Resource Partners L.P. (the "Partnership") engages principally in the business of owning, operating, managing and leasing a diversified portfolio of mineral properties in the United States, including interests in coal, trona and soda ash, oil and gas, construction aggregates, frac sand and other natural resources. As used in these Notes to Consolidated Financial Statements, the terms "NRP," "we," "us" and "our" refer to Natural Resource Partners L.P. and its subsidiaries, unless otherwise stated or indicated by context. Principles of Consolidation and Reporting The accompanying unaudited Consolidated Financial Statements of the Partnership have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") for interim financial information and with Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. As described in "Note 2. Segment Information", we recasted certain prior period amounts to conform to the way we internally manage and monitor segment performance. In particular, prior year general and administrative charges that were allocated to operating segments have been reclassified to Operating and maintenance expenses and Operating and maintenance expenses—affiliates on the Consolidated Statements of Comprehensive Income. The prior period reclassifications for new segments had no impact on the Partnership's consolidated financial position, net income (loss) or cash flows. On January 1, 2016, the Partnership adopted a new accounting standard using a retrospective approach that required the presentation of the Partnership's debt issuance costs as a direct deduction from the related debt liability, rather than recorded as an asset. The adoption resulted in a reclassification that reduced other current assets and short-term debt by $0.2 million and reduced other assets and long-term debt (including affiliate) by $13.8 million on the Partnership’s Consolidated Balance Sheet at December 31, 2015. In our opinion, all adjustments, consisting only of normal recurring adjustments necessary for a fair presentation, have been included. The interim financial statements should be read in conjunction with the audited financial statements and related notes included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2015. Interim results are not necessarily indicative of the results for a full year. Management’s Forecast, Strategic Plan and Going Concern Analysis While NRP has a diversified portfolio of assets and a history and continued forecast of profitable operations with positive operating cash flows, its operating results and credit metrics continue to be impacted by demand challenges for coal and excess worldwide supply of oil and gas. In particular, as described in Note 7. Debt and Debt—Affiliate, NRP Oil and Gas LLC ("NRP Oil and Gas") and NRP Operating LLC ("Opco"), both wholly owned subsidiaries of NRP, have debt agreements that contain customary financial covenants, including maintenance covenants, and other covenants. In addition, NRP has issued $425 million of 9.125% Senior Notes that are governed by an indenture (the "Indenture") containing customary incurrence-based financial covenants and other covenants, but not maintenance covenants. The following discussion presents management’s going concern analysis in light of management’s outlook and strategic plan to address its debt covenant compliance and maturities. Opco As of March 31, 2016 , Opco had $290.0 million of indebtedness outstanding under its revolving credit facility due October 2017 (the "Opco Credit Facility") and $544.9 million outstanding under several series of Private Placement Notes (the "Opco Private Placement Notes") (collectively referred to as the "Opco Debt agreements"). The maximum leverage ratio under the Opco Debt agreements is required to be below 4.0 x through March 31, 2016. Commencing with respect to the period ending June 30, 2016, the maximum leverage ratio reduces to 3.75 x and reduces again to 3.5 x commencing with respect to the period ending June 30, 2017. In addition, the Opco Debt agreements contain certain additional customary negative covenants that, among other items, restrict Opco’s ability to incur additional debt, grant liens on its assets, make investments, sell assets and engage in business combinations. Opco's leverage ratio was 3.09x at March 31, 2016. While we forecast that we will be in compliance with all of the covenants under the Opco Debt agreements through March 31, 2017, our forecast is sensitive to commodity pricing and counterparty risk. Breaches of the Opco Debt agreement covenants that are not waived or cured, to the extent possible, would result in an event of default under the Opco Debt agreements, and if such debt is accelerated by the lenders thereunder, such acceleration would also result in a cross-default under the Indenture. We are currently pursuing or considering a number of actions in order to mitigate the effects of further commodity price and market deterioration which could otherwise cause us to breach financial covenants under the Opco Debt agreements. These actions include (i) dispositions of assets, (ii) actively managing our debt capital structure through a number of potential alternatives, including exchange offers and non-traditional debt financing, (iii) minimizing our capital expenditures, (iv) obtaining waivers or amendments from our lenders, (v) effectively managing our working capital and (vi) improving our cash flows from operations. NRP Oil and Gas NRP Oil and Gas had $75.0 million outstanding under its senior secured, reserve-based revolving credit facility (the "RBL Facility") as of March 31, 2016 . The facility is secured by a first priority lien on substantially all of NRP Oil and Gas' assets and is not guaranteed by NRP or any other subsidiary of NRP. In March 2016, NRP Oil and Gas entered into an amendment to the RBL Facility (the “Fourth Amendment”) that included a $10.0 million repayment of principal, a $13.0 million reduction in borrowing capacity, and the easing or temporary easing of certain covenant requirements. Please see "Note 7. Debt and Debt—Affiliate" for further detail of the Fourth Amendment. While the Fourth Amendment alleviated certain covenant compliance issues, it did not change the fact that our current forecast indicates that NRP Oil and Gas may not be able to meet its leverage ratio during the next 12 months and that the borrowing base under the RBL Facility will be reduced by an amount greater than what NRP Oil and Gas would have the ability to pay within the required period of time. As a result, we believe there is substantial doubt about the ability of NRP Oil and Gas to continue as a going concern through March 31, 2017. In order to address this issue, we have initiated a process to sell all of NRP Oil and Gas' non-operating working interest properties in the Williston Basin within the next twelve months. As of March 31, 2016, we have classified the RBL Facility as Current portion of long-term debt, net on the Partnership's Consolidated Balance Sheets. An event of default under the RBL Facility and subsequent acceleration of that debt by the lenders thereunder would not result in a cross-default under the Indenture. NRP Oil and Gas is designated as an "Unrestricted Subsidiary" for purposes of the Indenture, which prevents an event of default under the RBL Facility and subsequent acceleration of that debt from triggering an event of default under the Indenture. In addition, there are no cross-defaults under the Opco Debt agreements as a result of a default under the RBL Facility. As a result, there would be no default or acceleration of indebtedness under the Indenture or under the Opco Debt agreements in the event NRP Oil and Gas is in default under the RBL Facility. Reverse Unit Split On January 26, 2016, the board of directors of our general partner approved a 1-for-10 reverse split on our common units, effective following market close on February 17, 2016. Pursuant to the authorization provided, the Partnership completed the 1-for-10 reverse unit split and its common units began trading on a reverse unit split-adjusted basis on the New York Stock Exchange on February 18, 2016. As a result of the reverse unit split, every 10 outstanding common units were combined into one common unit. The reverse unit split reduced the number of common units outstanding from 122.3 million units to 12.2 million units. All unit and per unit data included in these consolidated financial statements has been retroactively restated to reflect the reverse unit split. Recently Issued Accounting Standards Not Yet Adopted In May 2014, the Financial Accounting Standards Board ("FASB") amended its guidance on revenue recognition. The core principle of this amendment is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted for reporting periods beginning after December 15, 2016, including interim reporting periods within that period. This guidance can be adopted either retrospectively to each prior reporting period presented or as a cumulative-effect adjustment as of the date of adoption. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows. In August 2014, the FASB issued guidance on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The guidance is effective for interim and annual periods ending after December 15, 2016 and early adoption is permitted. The new guidance will require a formal assessment of going concern by management based on criteria prescribed in the new guidance, but will not impact the Partnership's financial position or results of operations. The Partnership is reviewing its policies and processes to ensure compliance with this new guidance. In July 2015, the FASB issued authoritative guidance which intended to simplify the measurement of inventory. This guidance requires an entity to measure inventory at the lower of cost or net realizable value. The amendments do not apply to inventory that is measured using last-in, first-out or the retail inventory method. This guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, with early adoption permitted. This guidance should be applied on a prospective basis. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows. In February 2016, the FASB issued authoritative lease guidance that establishes a right-of-use ("ROU") model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. The main difference between the current requirement under GAAP and the ROU model is the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information Due to acquisitions that diversified our natural resource asset base, effective for the quarter ended December 31, 2015, management revised the Partnership's operating segments to align with its management structure and organizational responsibilities and revised the information that its chief operating decision maker regularly reviews for purposes of allocating resources and assessing performance. As a result, effective for the quarter ended December 31, 2015, we reported our financial performance based on the new segments as described below. The Partnership's segments are strategic business units that offer products and services to different customer segments in different geographies within the U.S. and that are managed accordingly. NRP has the following four operating segments: Coal, Hard Mineral Royalty and Other —consists primarily of coal royalty, coal related transportation and processing assets, aggregate and industrial minerals royalty assets and timber. Our coal reserves are primarily located in Appalachia, the Illinois Basin and the Western United States. Our aggregates and industrial minerals are located in a number of states across the United States. In February 2016, we sold aggregates reserves and related royalty rights at three aggregates operations located in Texas, Georgia and Tennessee. Soda Ash —consists of the Partnership's 49% non-controlling equity interest in a trona ore mining operation and soda ash refinery in the Green River Basin, Wyoming. Ciner Resources LP, our operating partner, mines the trona, processes it into soda ash, and distributes the soda ash both domestically and internationally into the glass and chemicals industries. We receive regular quarterly distributions from this business. VantaCore —consists of our construction materials business acquired in October 2014 that operates hard rock quarries, an underground limestone mine, sand and gravel plants, asphalt plants and marine terminals. VantaCore operates in Pennsylvania, West Virginia, Tennessee, Kentucky and Louisiana. Oil and Gas —consists of our non-operated working interests, royalty interests and overriding royalty interests in oil and natural gas properties. Our primary interests in oil and natural gas producing properties are non-operated working interests located in the Williston Basin in North Dakota and Montana. We also own fee mineral, royalty or overriding royalty interests in oil and gas properties in Oklahoma and Louisiana. In February 2016, we sold royalty and overriding royalty interests in several producing properties located in the Appalachian Basin. Direct segment costs and certain costs incurred at a corporate level that are identifiable and that benefit the Partnership's segments are allocated to the operating segments. These allocated costs include costs of: taxes, legal, information technology and shared facilities services and are included in Operating and maintenance expenses and Operating and maintenance expenses—affiliates on the Consolidated Statements of Comprehensive Income. Prior year general and administrative charges that are allocated to the operating segments have been reclassified to operating and maintenance expenses. Intersegment sales are at prices that approximate market. Corporate and Financing includes functional corporate departments that do not earn revenues. Costs incurred by these departments include corporate headquarters and overhead, financing, centralized treasury and accounting and other corporate-level activity not specifically allocated to a segment. The following table summarizes certain financial information for each of the Partnership's operating segments (in thousands): Operating Segments For the Three Months Ended Coal, Hard Mineral Royalty and Other Soda Ash VantaCore Oil and Gas Corporate and Financing Total For the three months ended March 31, 2016 Revenues (including affiliates) $ 39,045 $ 9,801 $ 24,682 $ 7,298 $ — $ 80,826 Intersegment revenues (expenses) 21 — (21 ) — — — Gain on asset sales 1,590 — — 20,335 — 21,925 Operating and maintenance expenses (including affiliates) 7,380 — 22,156 5,114 — 34,650 Depreciation, depletion and amortization 6,762 — 3,562 4,419 — 14,743 Asset impairment 1,893 — — 137 — 2,030 Interest expense, net — — — — (23,729 ) (23,729 ) Net income (loss) 24,600 9,801 (1,036 ) 17,963 (27,901 ) 23,427 For the three months ended March 31, 2015 Revenues (including affiliates) $ 53,510 $ 12,523 $ 26,799 $ 14,779 $ — $ 107,611 Gain on asset sales 1,615 — — 451 — 2,066 Operating and maintenance expenses (including affiliates) 8,414 — 25,434 6,649 — 40,497 Depreciation, depletion and amortization 10,016 — 3,856 11,520 — 25,392 Interest expense, net — — — — (22,928 ) (22,928 ) Net income (loss) 36,695 12,523 (2,491 ) (2,939 ) (26,299 ) 17,489 Total assets March 31, 2016 1,016,827 258,939 196,720 132,324 20,083 1,624,893 December 31, 2015 1,047,922 261,942 200,348 158,862 961 1,670,035

Equity Investment

Equity Investment	3 Months Ended
	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment	Equity Investment We account for our 49% investment in Ciner Wyoming LLC ("Ciner Wyoming", and formerly "OCI Wyoming LLC") using the equity method of accounting. Ciner Wyoming distributed $12.3 million and $10.9 million to us in the three months ended March 31, 2016 and 2015 , respectively. The difference between the amount at which the investment in Ciner Wyoming is carried and the amount of underlying equity in Ciner Wyoming's net assets was $153.6 million and $154.8 million as of March 31, 2016 and December 31, 2015 , respectively. This excess basis relates to plant, property and equipment and right to mine assets. The excess basis difference that relates to property, plant and equipment is being amortized into income using the straight-line method over a weighted average of 28 years . The excess basis difference that relates to right to mine assets is being amortized into income using the units of production method. Our equity in the earnings of Ciner Wyoming is summarized as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Income allocation to NRP’s equity interests $ 10,996 $ 13,727 Amortization of basis difference (1,195 ) (1,204 ) Equity in earnings of unconsolidated investment $ 9,801 $ 12,523 The results of Ciner Wyoming’s operations are summarized as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Sales $ 114,384 $ 120,430 Gross profit 28,251 32,724 Net Income 22,441 28,014 The financial position of Ciner Wyoming is summarized as follows (in thousands): March 31, December 31, (Unaudited) Current assets $ 139,185 $ 144,695 Noncurrent assets 233,236 233,845 Current liabilities 46,881 43,018 Noncurrent liabilities 110,518 116,808 The purchase agreement for the acquisition of the Partnership’s interest in Ciner Wyoming, formerly OCI Wyoming, required the Partnership to pay additional contingent consideration to Anadarko to the extent certain performance criteria described in the purchase agreement were met by Ciner Wyoming in any of the years 2013, 2014 or 2015. During the first quarters of 2014, 2015 and 2016, the Partnership paid contingent consideration of $0.5 million , $3.8 million and $7.2 million , respectively, in contingent consideration to Anadarko for performance criteria met by Ciner Wyoming in 2013, 2014 and 2015, respectively. The Partnership has no further contingent consideration payments due to Anadarko under the purchase agreement.

Plant and Equipment

Plant and Equipment	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Plant and Equipment	Plant and Equipment The Partnership’s plant and equipment consist of the following (in thousands): March 31, December 31, (Unaudited) Plant and equipment at cost $ 77,565 $ 92,203 Construction in process 1,323 1,074 Less accumulated depreciation (21,444 ) (32,038 ) Total plant and equipment, net $ 57,444 $ 61,239 Depreciation expense related to the Partnership's plant and equipment totaled $3.4 million and $4.5 million for the three months ended March 31, 2016 and 2015, respectively.

Mineral Rights

Mineral Rights	3 Months Ended
	Mar. 31, 2016
Extractive Industries [Abstract]
Mineral Rights	Mineral Rights The Partnership’s mineral rights consist of the following (in thousands): March 31, 2016 (Unaudited) Carrying Value Accumulated Depletion Net Book Value Coal, Hard Mineral Royalty and Other $ 1,269,633 $ (437,628 ) $ 832,005 VantaCore 112,700 (3,475 ) 109,225 Oil and Gas 136,392 (16,793 ) 119,599 Total $ 1,518,725 $ (457,896 ) $ 1,060,829 December 31, 2015 Carrying Value Accumulated Depletion Net Book Value Coal, Hard Mineral Royalty and Other $ 1,278,274 $ (432,260 ) $ 846,014 VantaCore 112,700 (3,082 ) 109,618 Oil and Gas 155,293 (16,898 ) 138,395 Total $ 1,546,267 $ (452,240 ) $ 1,094,027 Depletion expense related to the Partnership’s mineral rights totaled $10.3 million and $19.9 million for the three months ended March 31, 2016 and 2015 , respectively. Sales of Royalty Properties As discussed in Note 1. "Basis of Presentation," we are currently pursuing or considering a number of actions, including dispositions of assets, in order to mitigate the effects of further commodity price and market deterioration which could otherwise cause us to breach financial covenants under our debt agreements. As part of this plan, the Partnership sold the following assets during the three months ended March 31, 2016: 1) Oil and gas royalty and overriding royalty interests in several producing properties located in the Appalachian Basin for $37.5 million . The effective date of the sale was January 1, 2016, and the Partnership recorded a $20.3 million gain from this sale included in Gain on asset sales on its Consolidated Statement of Comprehensive Income. 2) Hard mineral reserves and related royalty rights at three aggregates operations located in Texas, Georgia and Tennessee for $10.0 million . The effective date of the sale was February 1, 2016, and the Partnership recorded a $1.6 million gain from this sale included in Gain on asset sales on its Consolidated Statement of Comprehensive Income.

Intangible Assets (Including Af

Intangible Assets (Including Affiliate)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets (Including Affiliate)	Intangible Assets (Including Affiliate) The Partnership's intangible assets—affiliate relate to above market coal transportation contracts with subsidiaries of Foresight Energy LP ("Foresight Energy") in which we receive throughput fees for the handling and transportation of coal. March 31, December 31, (Unaudited) Intangible assets—affiliate $ 81,109 $ 81,109 Less accumulated amortization—affiliate (28,835 ) (28,112 ) Total intangible assets, net—affiliate $ 52,274 $ 52,997 Amortization expense related to the Partnership's intangible assets—affiliate totaled $0.7 million and $0.8 million for the three months ended March 31, 2016 and 2015, respectively. The Partnership's intangible assets consist of permits, aggregate-related trade names and other agreements as follows (in thousands): March 31, December 31, (Unaudited) Intangible assets 5,076 5,076 Less accumulated amortization (1,375 ) (1,146 ) Total intangible assets, net $ 3,701 $ 3,930 Amortization expense related to the Partnership's intangible assets totaled $0.2 million for both the three months ended March 31, 2016 and 2015.

Debt and Debt - Affiliate

Debt and Debt - Affiliate	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Debt and Debt—Affiliate	Debt and Debt—Affiliate As of March 31, 2016 and December 31, 2015, debt and debt—affiliate consisted of the following (in thousands): March 31, December 31, (Unaudited) NRP LP debt: 9.125% senior notes, with semi-annual interest payments in April and October, due October 2018, $300 million issued at 99.007% and $125 million issued at 99.5% $ 425,000 $ 425,000 Opco debt (1): $300 million floating rate revolving credit facility, due October 2017 290,000 290,000 4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, due June 2018 13,850 13,850 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2019 64,286 85,714 5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, due July 2020 38,462 38,462 5.31% utility local improvement obligation, with annual principal and interest payments in February, due March 2021 960 1,153 5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, due June 2023 21,600 21,600 4.73% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2023 60,000 60,000 5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 120,000 135,000 8.92% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 36,364 40,909 5.03% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 148,077 148,077 5.18% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 42,308 42,308 NRP Oil and Gas debt: Reserve-based revolving credit facility due November 2019 75,000 85,000 Total debt at face value $ 1,335,907 $ 1,387,073 Net unamortized debt discount (1,889 ) (2,077 ) Net unamortized debt issuance costs (1) (12,683 ) (14,040 ) Total debt, net $ 1,321,335 $ 1,370,956 Less: current portion of long-term debt 154,441 80,745 Total long-term debt $ 1,166,894 $ 1,290,211 (1) See Note 1. " Basis of Presentation" for discussion of debt issuance costs reclassification upon adoption of new accounting standard on January 1, 2016. NRP Debt NRP Senior Notes In September 2013, NRP, together with NRP Finance Corporation ("NRP Finance"), a wholly owned subsidiary of NRP, as co-issuer, issued $300.0 million of 9.125% Senior Notes due 2018 at an offering price of 99.007% of par (the "NRP Senior Notes"). Net proceeds after expenses from the issuance of NRP Senior Notes were approximately $289.0 million . The NRP Senior Notes call for semi-annual interest payments on April 1 and October 1 of each year, and will mature on October 1, 2018. In October 2014, NRP, together with NRP Finance as co-issuer, issued an additional $125.0 million of the NRP Senior Notes at an offering price of 99.5% of par. The additional issuance constituted the same series of securities as the existing NRP Senior Notes. Net proceeds of $122.6 million from the additional issuance of the NRP Senior Notes were used to fund a portion of the purchase price of NRP’s acquisition of non-operated working interests in oil and gas assets located in the Williston Basin in North Dakota. NRP and NRP Finance have the option to redeem the NRP Senior Notes, in whole or in part, at any time on or after April 1, 2016, at fixed redemption prices specified in the indenture governing the NRP Senior Notes (the "Indenture"). The Indenture contains covenants that, among other things, limit the ability of NRP and certain of its subsidiaries to incur or guarantee additional indebtedness. Under the Indenture, NRP 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 and certain of its subsidiaries to incur additional indebtedness is further limited in the event the amount of indebtedness of NRP and certain of its subsidiaries that is senior to NRP’s unsecured indebtedness exceeds certain thresholds. As of March 31, 2016 and December 31, 2015, NRP was in compliance with the terms of the covenants contained under the Indenture. Opco Debt All of Opco’s debt is guaranteed by its wholly owned subsidiaries and is secured by certain of the assets of Opco and its wholly owned subsidiaries other than NRP Trona LLC, as further described below. As of March 31, 2016 and December 31, 2015, Opco was in compliance with the terms of the financial covenants contained in its debt agreements. Revolving Credit Facility In June 2015, Opco entered into a $300.0 million Third Amended and Restated Credit Agreement (the "A&R Revolving Credit Facility"), which amended and restated Opco’s $300.0 million Second Amended and Restated Credit Agreement due August 2016. The A&R Revolving Credit Facility matures on October 2, 2017 , is guaranteed by all of Opco’s wholly owned subsidiaries, and is secured by liens on certain of the assets of Opco and its subsidiaries, as further described below. Initially, indebtedness under the A&R Revolving Credit Facility bore interest, at Opco's option, at a rate of 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 2.375% ; or • a rate equal to LIBOR plus 3.375% Subsequent to the delivery of financial statements for the year ended December 31, 2015 to the lenders in March 2016, indebtedness under the A&R Revolving Credit Facility bears interest, at Opco's option, at a rate of 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 1.50% to 2.50% or • a rate equal to LIBOR plus an applicable margin ranging from 2.50% to 3.50% The weighted average interest rates for the borrowings outstanding under the A&R Revolving Credit Facility for the three months ended March 31, 2016 and 2015 were 3.80% and 1.94% , respectively. Opco will incur a commitment fee on the unused portion of the revolving credit facility at a rate of 0.50% per annum. Opco may prepay all amounts outstanding under the A&R Revolving Credit Facility at any time without penalty. The A&R Revolving Credit Facility contains financial covenants requiring Opco to maintain: • a leverage ratio of consolidated indebtedness to consolidated EBITDDA (as defined in the A&R Revolving Credit Facility) not to exceed: ◦ 4.0 to 1.0 for each fiscal quarter ending on or before March 31, 2016; ◦ 3.75 to 1.0 for each subsequent fiscal quarter ending on or before March 31, 2017; and ◦ 3.5 to 1.0 for each fiscal quarter ending on or after June 30, 2017; and • a ratio of consolidated EBITDDA to consolidated fixed charges (consisting of consolidated interest expense and consolidated lease expense) of not less than 3.5 to 1.0. As of March 31, 2016, Opco's leverage ratio was 3.09x , and fixed charge coverage ratio was 5.43 x. The A&R Revolving Credit Facility contains certain additional customary negative covenants that, among other items, restrict Opco’s ability to incur additional debt, grant liens on its assets, make investments, sell assets and engage in business combinations. Included in the investment covenant are restrictions upon Opco’s ability to acquire assets where Opco does not maintain certain levels of liquidity. The A&R Revolving Credit Facility also contains customary events of default, including cross-defaults under Opco’s senior notes (as described below). The A&R Revolving Credit Facility is collateralized and secured by liens on certain of Opco’s assets with a carrying values of $698.1 million and $709.9 million classified as Land, Mineral rights and Plant and equipment on the Partnership’s Consolidated Balance Sheet as of March 31, 2016 and December 31, 2015, respectively. The collateral includes (1) the equity interests in all of Opco’s wholly owned subsidiaries, other than NRP Trona LLC (which owns a 49% non-controlling equity interest in Ciner Wyoming), (2) the personal property and fixtures owned by Opco’s wholly owned subsidiaries, other than NRP Trona LLC, (3) Opco’s material coal royalty revenue producing properties, (4) real property associated with certain of VantaCore’s construction aggregates mining operations, and (5) certain of Opco’s coal-related infrastructure assets. Opco Senior Notes Opco has issued several series of private placement senior notes (the “Opco Senior Notes") with various interest rates and principal due dates. As of March 31, 2016, and December 31, 2015, the Opco Senior Notes had cumulative principal balances of $544.9 million and $585.9 million , respectively. Opco made principal payments of $41.0 million on the Opco Senior Notes during each of the three months ended March 31, 2016 and 2015. The Note Purchase Agreements relating to the Opco Senior Notes contain 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 (as defined in the note purchase agreement) 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% Opco Senior Notes also provide that in the event that Opco’s leverage ratio of consolidated indebtedness to consolidated EBITDDA (as defined in the Note Purchase Agreements) 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. Opco has not exceeded the 3.75 to 1.00 ratio at the end of any fiscal quarter through March 31, 2016. In connection with the entry into the A&R Revolving Credit Facility in June 2015, Opco entered into the Third Amendment to the Note Purchase Agreements (the "NPA Amendment") that provides for the security of the Opco Senior Notes by the same collateral package pledged by Opco and its subsidiaries to secure the A&R Revolving Credit Facility, as described above. In addition, the NPA Amendment includes a covenant that provides that, in the event Opco or any of its subsidiaries is subject to any additional or more restrictive covenants under the agreements governing its material indebtedness (including the A&R Revolving Credit Facility, and all renewals, amendments or restatements thereof), such covenants shall be deemed to be incorporated by reference in the Opco Senior Notes and the holders of the Opco Senior Notes shall receive the benefit of such additional or more restrictive covenants to the same extent as the lenders under such material indebtedness agreement. NRP Oil and Gas Debt The RBL Facility At March 31, 2016 and December 31, 2015, there was $75.0 million and $85.0 million respectively, outstanding under the RBL Facility. NRP Oil and Gas was in compliance with the terms of the covenants contained in the RBL Facility as of both March 31, 2016 and December 31, 2015. In August 2013, NRP Oil and Gas entered into the RBL Facility, a 5 -year, $100.0 million senior secured, reserve-based revolving credit facility, in order to fund capital expenditure requirements related to the development of the oil and gas assets in which it owns non-operated working interests. In connection with the closing of the Sanish Field acquisition in November 2014, the RBL Facility was amended to increase its size to $500.0 million with an initial borrowing base of $137.0 million , and the maturity date thereof was extended to November 2019 . The RBL Facility is secured by a first priority lien and security interest in substantially all of the assets of NRP Oil and Gas. NRP Oil and Gas is the sole obligor under the RBL Facility, and neither the Partnership nor any of its other subsidiaries is a guarantor of the RBL Facility. The maximum amount available under the RBL Credit Facility is subject to semi-annual redeterminations of the borrowing base in May and November of each year, based on the value of the proved oil and natural gas reserves of NRP Oil and Gas, in accordance with the lenders’ customary procedures and practices. NRP Oil and Gas and the lenders each have a right to one additional redetermination each year. In April 2015, the lenders completed their semi-annual redetermination of the borrowing base under the RBL Credit Facility and the $137.0 million borrowing base was redetermined to $105.0 million . In October 2015, the lenders under the RBL Credit Facility completed their semi-annual redetermination and the $105.0 million borrowing base was redetermined to $88.0 million . The Company repaid $25.0 million of outstanding borrowings under the RBL Credit Facility during the year ended December 31, 2015. At December 31, 2015, there was $85.0 million outstanding under the RBL Credit Facility. In March 2016, the Company entered into an amendment to the RBL Facility (the “Fourth Amendment”) and repaid $10.0 million thereunder, which reduced the outstanding balance thereunder to $75.0 million . In connection with such repayment, the borrowing base under the RBL Facility was reduced from $88.0 million to $75.0 million in lieu of the May 2016 borrowing base redetermination. Per the Fourth Amendment, the borrowing base will be reduced to $70.0 million on August 1, 2016, and to $50.0 million on October 1, 2016, with any outstanding amounts under the RBL Facility in excess of the reduced principal amounts due and payable on their respective day. The next scheduled redetermination of the borrowing base under the RBL Facility will occur in November 2016. The Fourth Amendment amends the financial covenants contained in the RBL Facility as follows: • The maximum total leverage ratio (defined as the ratio of the total debt to EBITDAX) will be increased from 3.5 x to 4.0 x at March 31, 2016 and 4.5 x at June 30, 2016. Thereafter, the total leverage ratio will decrease to 3.5 x for the remainder of the term of the RBL Facility. • The minimum current ratio will decrease from 1.0 x to 0.75 x at March 31, 2016 and June 30, 2016 and revert to 1.0 x thereafter for the remainder of the term of the RBL Facility. As of March 31, 2016, NRP Oil and Gas' leverage ratio was 3.10 x, and current ratio was 1.94 x. In addition, effective on the date of the Fourth Amendment, indebtedness under the RBL Facility bears interest, at the Company's option, at: • 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 4.0% ; or • a rate equal to LIBOR, plus an applicable margin of 4.0% The commitment fee on the unused portion of the borrowing base under the RBL Facility was also amended to be a flat 0.50% fee. The Fourth Amendment contains several other amendments, including a requirement for NRP Oil and Gas to pay down the RBL Facility each month with excess cash flow (which amounts may not be reborrowed and will result in a corresponding reduction in the borrowing base) and a requirement to use the net proceeds of any asset sales to repay the RBL Facility (which amounts may not be reborrowed and will result in a corresponding reduction in the borrowing base). In addition, the Fourth Amendment waives the delivery of 2015 audited financial statements containing an audit opinion containing "a "going concern" or like qualification or exception" as an event of default under the RBL Facility.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Partnership’s financial instruments consist of cash and cash equivalents, accounts receivable, contracts receivable—affiliate, accounts payable and debt. The carrying amounts reported on the Partnership's Consolidated Balance Sheets for cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their short-term nature. The Partnership used quotations obtained for comparable instruments on the closing trading prices near period end to determine the fair value of its contracts receivable—affiliate, which resulted in a Level 3 fair value measurement. The estimated fair value of the Partnership's contracts receivable—affiliate was $3.7 million and $4.2 million at March 31, 2016 and December 31, 2015, respectively. The following table (in thousands) shows the face and estimated fair values of the Partnership's debt and debt—affiliate: March 31, 2016 December 31, 2015 Debt at Face Value Estimated Fair Value Debt at Face Value Estimated Fair Value (Unaudited) NRP Senior Notes (1) $ 425,000 $ 272,000 $ 425,000 $ 277,313 Opco Senior Notes and utility local improvement obligation (2) 545,907 349,380 587,073 383,065 Opco Revolving Credit Facility (3) 290,000 290,000 290,000 290,000 NRP Oil and Gas RBL Facility (3) 75,000 75,000 85,000 85,000 (1) The Level 1 fair value is based upon quotations obtained for identical instruments on the closing trading prices near period end. (2) The Level 3 fair value is estimated by management using quotations obtained for comparable instruments on the closing trading prices near period end. (3) The Level 3 fair value approximates the carrying amount because the interest rates are variable and reflective of market rates and the terms of the credit facility allow the Partnership to repay this debt at any time without penalty.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Reimbursements to Affiliates of our 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 services provided to the Partnership and for expenses incurred on the Partnership’s behalf. Employees of Quintana Minerals Corporation ("QMC") and Western Pocahontas Properties Limited Partnership ("WPPLP"), affiliates of the Partnership, provide their services to manage the Company's business. QMC and WPPLP charge the Partnership the portion of their employee salary and benefits costs related to their employee services provided to NRP. In addition, the Partnership receives non-cash equity contributions from its general partner related to compensation paid directly by the general partner and not reimbursed by the Partnership. These amounts are presented as non-cash equity contributions on the Partnership's Consolidated Statements of Partners' Capital. These QMC and WPPLP employee management service costs and non-cash equity compensation expenses are presented as Operating and maintenance expenses—affiliates, net and General and administrative—affiliates on the Consolidated Statements of Comprehensive Income. NRP also reimburses overhead costs incurred by its affiliates to manage the Partnership's business. These overhead costs include certain legal, accounting, treasury, information technology, insurance, administration of employee benefits and other corporate services incurred by the Partnership’s general partner and its affiliates and are presented as Operating and maintenance expenses—affiliates, net and General and administrative—affiliates on the Consolidated Statements of Comprehensive Income. The Partnership had Accounts payable—affiliates to Quintana Minerals Corporation of $0.6 million and $1.1 million at March 31, 2016 and December 31, 2015, respectively, for services provided by Quintana Minerals Corporation to the Partnership. The Partnership had Accounts payable—affiliates to WPPLP of $0.6 million and $0.3 million at March 31, 2016 and December 31, 2015, respectively. Direct general and administrative expenses charged to the Partnership by WPPLP and Quintana Minerals Corporation are as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Operating and maintenance expenses—affiliates, net $ 2,776 $ 2,702 General and administrative—affiliates 937 1,084 Cline Affiliates Various companies controlled by Chris Cline, including Foresight Energy LP ("Foresight Energy"), lease coal reserves from the Partnership, and the Partnership also leases coal transportation assets to them for a fee. Mr. Cline, both individually and through another affiliate, Adena Minerals, LLC, owns a 31% interest in the NRP's general partner, as well as approximately 0.5 million of NRP's common units at March 31, 2016. Coal related revenues from Foresight Energy totaled $10.1 million and $18.3 million for the three months ended March 31, 2016 and 2015, respectively. As of March 31, 2016 and December 31, 2015, the Partnership had Accounts receivable—affiliates from Foresight Energy of $7.4 million and $6.4 million , respectively. The Partnership had recorded $81.6 million and $82.6 million in minimum royalty payments as Deferred revenue—affiliates at March 31, 2016 and December 31, 2015, respectively. The Partnership owns and leases rail load out and associated facilities to Foresight Energy at Foresight Energy's Sugar Camp mine. The lease agreement is accounted for as a direct financing lease. Total projected remaining payments under the lease at March 31, 2016 were $80.2 million with unearned income of $34.5 million , and the net amount receivable was $45.7 million , of which $2.1 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliate on the accompanying Consolidated Balance Sheets. Total projected remaining payments under the lease at December 31, 2015 were $81.2 million with unearned income of $35.4 million and the net amount receivable was $45.9 million , of which $2.0 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliates on the accompanying Consolidated Balance Sheets. The Partnership holds a contractual overriding royalty interest from a subsidiary of Foresight Energy that provides for payments based upon production from specific tons at Foresight Energy's 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 March 31, 2016 was $4.5 million , of which $2.2 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliate. The net amount receivable under the agreement as of December 31, 2015 was $4.9 million , of which $1.5 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliate on the accompanying Consolidated Balance Sheets. Long-Term Debt—Affiliate Cline Trust Company, LLC owns approximately 0.54 million of the Partnership’s common units and $20.0 million in principal amount of the Partnership’s 9.125% Senior Notes due 2018. The members of the Cline Trust Company are four trusts for the benefit of the children of Chris Cline, each of which owns an approximately equal membership interest in the Cline Trust Company. Cline Trust Company, LLC purchased the $20.0 million of the Partnership’s 9.125% Senior Notes due 2018 in the Partnership’s offering of $125.0 million additional principal amount of such notes in October 2014 at the same price as the other purchasers in that offering. The balance on this portion of the Partnership’s 9.125% Senior Notes due 2018 was $19.9 million as of March 31, 2016 and is included in Long-term debt, net—affiliate on the accompanying Consolidated Balance Sheet. Quintana Capital Group GP, Ltd. Corbin J. Robertson, Jr. is a principal in Quintana Capital Group GP, Ltd. ("Quintana Capital"), 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 March 31, 2016, a fund controlled by Quintana Capital owned a majority interest in Corsa Coal Corp. ("Corsa"), 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. Coal related revenues from Corsa totaled $0.5 million and $0.8 million for the three months ended March 31, 2016 and 2015, respectively. The Partnership had recorded $0.3 million in minimum royalty payments as Deferred revenue—affiliates at both March 31, 2016 and December 31, 2015. The Partnership also had Accounts receivable—affiliates totaling $0.1 million and $0.2 million from Corsa at March 31, 2016 and December 31, 2015, respectively. WPPLP Production Royalty and Overriding Royalty For the three months ended March 31, 2016, the Partnership recorded $0.6 million in operating and maintenance expenses—affiliates related to a non-participating production royalty payable to WPPLP pursuant to a conveyance agreement entered into in 2007. These charges were zero for the three months ended March 31, 2015. The Partnership had Other assets—affiliate from WPPLP of $0.5 million and $1.1 million at March 31, 2016 and December 31, 2015, respectively related to a non-production royalty receivable from WPPLP for overriding royalty interest on a mine.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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. Since 2013, several citizen group lawsuits have been filed against landowners alleging ongoing discharges of pollutants, including selenium and conductivity, from valley fills located at reclaimed mountaintop removal mining sites in West Virginia. In each case, the mine on the subject property had been closed, the property had been reclaimed, and the state reclamation bond had been released. Any determination that a landowner or lessee has liability for discharges from a previously reclaimed mine site could result in substantial compliance costs or fines and would result in uncertainty as to continuing liability for completed and reclaimed coal mine operations. A subsidiary of the Partnership has been named as a defendant in one of these lawsuits. Given the early stage of this ongoing litigation, the Partnership currently cannot reasonably estimate a range of potential loss, if any, related to this matter. Foresight Energy Disputes On November 24, 2015, we filed a lawsuit against Foresight Energy’s subsidiary, Hillsboro Energy LLC ("Hillsboro"), in the Circuit Court of the Fourth Judicial Circuit in Montgomery County, Illinois. The lawsuit alleges, among other items, breach of contract by Hillsboro resulting from a wrongful declaration of force majeure at Hillsboro’s Deer Run mine in July 2015. In late March 2015, elevated carbon monoxide readings were detected at the Deer Run mine, and coal production at the mine was idled. In July 2015, we received the notice declaring a force majeure event at the mine as a result of the elevated carbon monoxide levels. The effect of a valid force majeure declaration would relieve Foresight Energy of its obligation to pay us minimum deficiency payments of $7.5 million per quarter, or $30.0 million per year. Foresight Energy's failure to make the deficiency payment with respect to 2015 and first quarter of 2016 resulted in a $23.6 million cash impact to us. Such amount will increase for each quarter during which mining operations continue to be idled. We do not currently have an estimate as to when the mine will resume coal production. If the mine remains idled for an extended period or if the mine is permanently closed, our financial condition could be adversely affected. On April 1, 2016, we filed a lawsuit against Macoupin Energy, LLC (“Macoupin”), a subsidiary of Foresight Energy, in Macoupin County, Illinois. The lawsuit alleges that Macoupin has failed to comply with the terms of its coal mining, rail loadout and rail loop leases by incorrectly recouping previously paid minimum royalties. Foresight Energy’s failure to properly calculate its recoupable balance and failure to make payments in accordance with these lease agreements with respect to the third and fourth quarters of 2015 and the first quarter of 2016 resulted in a $4.7 million negative cash impact to us. While the Partnership plans to pursue its claim, a valuation allowance for the receivable amount has been recorded given the early stage of this ongoing litigation. It is possible that the Partnership’s current estimate of the valuation allowance related to this matter could change, perhaps materially, in the future.

Major Customers

Major Customers	3 Months Ended
	Mar. 31, 2016
Risks and Uncertainties [Abstract]
Major Customers	Major Customers Revenues from Foresight Energy represented $10.1 million , or 9.8% and $18.3 million , or 16.7% of total revenues and other income for the three months ended March 31, 2016 and 2015, respectively. The revenues from Foresight Energy are spread out over a number of different mining operations and leases. No other customers exceeded ten percent of total revenues and other income during the first quarter of 2016 or 2015.

Unit-Based Compensation

Unit-Based Compensation	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	Unit-Based Compensation At the time of our initial public offering, 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 Committee ("CNG Committee") of GP Natural Resource Partners LLC’s board of directors administers the Long-Term Incentive Plan and has historically approved annual awards of phantom units that vest four years from the date of grant. In February 2016, the CNG Committee adopted and the Board approved a new cash-based long-term incentive plan to the employees of its affiliates who perform services for the Partnership. Subject to the rules of the exchange upon which the common units are listed at the time, the board of directors and the compensation 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. Phantom units are incentive based equity awards issued to employees over a vesting period that entitle the grantee to receive the cash equivalent to the value of a unit of our common units upon each vesting. The Partnership records compensation cost equal to the fair value of the award at the measurement date, which is determined to be the earlier of the performance commitment date or the service completion date. In addition, compensation cost for unvested phantom unit awards is adjusted quarterly for any changes in the Partnership’s unit price. 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 20 trading days prior to the vesting date. The compensation 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 compensation committee provides otherwise. In connection with the phantom unit awards, the Compensation, Nominating and Governance Committee also granted tandem Distribution Equivalent Rights ("DERs"), which entitle the holders to receive distributions equal to the distributions paid on the Partnership’s common units between the date the units are granted and the vesting date. The DERs are payable in cash upon vesting but may be subject to forfeiture if the grantee ceases employment prior to vesting. A summary of activity in the outstanding grants during 2016 is as follows (in thousands): Phantom Units Outstanding grants at January 1, 2016 126 Grants during the period — Grants vested and paid during the period (28 ) Forfeitures during the period (3 ) Outstanding grants at March 31, 2016 95 Grants typically vest at the end of a four -year period and are paid in cash upon vesting. The Partnership recorded a credit to general and administrative expenses related to its Long-Term Incentive Plan of less than $0.1 million and $0.1 million for the three months ended March 31, 2016 and 2015, respectively, due to the decline in the market price of the Partnership's common units. In connection with the Long-Term Incentive Plan, payments are typically made during the first quarter of the year. Payments of $1.5 million and $4.4 million were made during the three months ended March 31, 2016 and 2015, respectively. The unaccrued cost associated with unvested outstanding grants and related DERs at March 31, 2016 and December 31, 2015, was $0.4 million and $0.7 million , respectively.

Cash Distributions

Cash Distributions	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Cash Distributions	Cash Distributions The following table shows the distributions paid by the Partnership during the three months ended March 31, 2016 and 2015: Total Distributions (In thousands) Date Paid Period Covered by Distribution Distribution per Common Unit Common Units GP Interest Total 2016 February 12, 2016 October 1 - December 31, 2015 $ 0.45 $ 5,503 $ 113 $ 5,616 2015 February 13, 2015 October 1 - December 31, 2014 $ 3.50 $ 42,804 $ 874 $ 43,678

Supplementary Unrestricted Subs

Supplementary Unrestricted Subsidiary Information	3 Months Ended
	Mar. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Supplementary Unrestricted Subsidiary Information	Supplementary Unrestricted Subsidiary Information The following is presented as supplementary data as required by the Indenture governing the NRP Senior Notes. As described in Note 1. "Basis of Presentation", in February 2016, the Partnership designated NRP Oil and Gas as an Unrestricted Subsidiary for purposes of the Indenture. In addition, the Partnership has designated BRP LLC, a joint venture in which the Partnership owns a 51% interest, and Coval Leasing Company, LLC, a wholly owned subsidiary of BRP LLC, as Unrestricted Subsidiaries for purposes of the Indenture. The information below may not necessarily be indicative of the results of operations, or financial position had the subsidiaries operated as independent entities. There were no transactions between the Partnership's Restricted Subsidiaries and its Unrestricted Subsidiaries. In accordance with the requirements of the Indenture, the following condensed consolidating financial information presents the financial condition and results of operations of the Partnership and its Restricted Subsidiaries and its Unrestricted Subsidiaries: CONDENSED CONSOLIDATING BALANCE SHEETS (in thousands) March 31, 2016 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Eliminations Total ASSETS Current assets (including affiliates) $ 10,101 $ 109,133 $ (217 ) $ 119,017 Mineral rights, net 131,905 928,924 — 1,060,829 Equity in unconsolidated investment — 258,939 — 258,939 Other non-current assets (including affiliates) 734 185,374 — 186,108 Total assets $ 142,740 $ 1,482,370 $ (217 ) $ 1,624,893 LIABILITIES AND CAPITAL Current portion of long-term debt, net $ 73,696 $ 80,745 $ — $ 154,441 Other current liabilities (including affiliates) 6,217 42,636 (27 ) 48,826 Long-term debt, net (including affiliate) — 1,166,894 — 1,166,894 Other non-current liabilities (including affiliates) 4,778 159,679 — 164,457 Partners' capital 61,494 32,365 (190 ) 93,669 Non-controlling interest (3,445 ) 51 — (3,394 ) Total liabilities and capital $ 142,740 $ 1,482,370 $ (217 ) $ 1,624,893 December 31, 2015 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Eliminations Total ASSETS Current assets (including affiliates) $ 21,540 $ 100,178 $ (589 ) $ 121,129 Mineral rights, net 134,445 959,582 — 1,094,027 Equity in unconsolidated investment — 261,942 — 261,942 Other non-current assets (including affiliates) (1) 887 192,050 — 192,937 Total assets $ 156,872 $ 1,513,752 $ (589 ) $ 1,670,035 LIABILITIES AND CAPITAL Current portion of long-term debt, net (1) $ — $ 80,745 $ — $ 80,745 Other current liabilities (including affiliates) 7,351 48,356 (43 ) 55,664 Long-term debt, net (including affiliate) (1) 83,600 1,206,611 — 1,290,211 Other non-current liabilities (including affiliates) 4,703 165,770 — 170,473 Partners' capital 64,663 12,219 (546 ) 76,336 Non-controlling interest (3,445 ) 51 — (3,394 ) Total liabilities and capital $ 156,872 $ 1,513,752 $ (589 ) $ 1,670,035 (1) See Note 1. " Basis of Presentation" for discussion of debt issuance costs reclassification upon adoption of new accounting standard on January 1, 2016. CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (in thousands) Three Months Ended March 31, 2016 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Total Revenues $ 7,323 $ 95,428 $ 102,751 Operating expenses 9,401 46,194 55,595 Income (loss) from operations (2,078 ) 49,234 47,156 Other expense, net 1,090 22,639 23,729 Net income (loss) (3,168 ) 26,595 23,427 Add: comprehensive loss from unconsolidated investment and other — (545 ) (545 ) Comprehensive income (loss) $ (3,168 ) $ 26,050 $ 22,882 Three Months Ended March 31, 2015 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Total Revenues $ 14,900 $ 94,777 $ 109,677 Operating expenses 16,748 52,512 69,260 Income (loss) from operations (1,848 ) 42,265 40,417 Other expense, net 808 22,120 22,928 Net income (loss) (2,656 ) 20,145 17,489 Add: comprehensive loss from unconsolidated investment and other — (965 ) (965 ) Comprehensive income (loss) $ (2,656 ) $ 19,180 $ 16,524

Deferred Revenue and Deferred R

Deferred Revenue and Deferred Revenue - Affiliate	3 Months Ended
	Mar. 31, 2016
Deferred Revenue Disclosure [Abstract]
Deferred Revenue and Deferred Revenue - Affiliate	Deferred Revenue and Deferred Revenue—Affiliate Most of the Partnership’s coal and aggregates lessees must make minimum annual or quarterly payments which are generally recoupable over certain time periods. These minimum payments are recorded as deferred revenue when received. The deferred revenue attributable to the minimum payment is recognized as revenue based upon the underlying mineral lease when the lessee recoups the minimum payment through production or in the period immediately following the expiration of the lessee’s ability to recoup the payments. The Partnership’s deferred revenue (including affiliate) consist of the following (in thousands): March 31, December 31, (Unaudited) Deferred revenue $ 76,750 $ 80,812 Deferred revenue—affiliate 81,868 82,853 Total deferred revenue (including affiliate) $ 158,618 $ 163,665 The Partnership recognized the following amounts of deferred revenue (including affiliate) attributable to previously paid minimums as Coal, hard mineral royalty and other revenue (in thousands): Three Months Ended 2016 2015 (Unaudited) Coal, hard mineral royalty and other (1) $ 6,094 $ 1,063 Coal, hard mineral royalty and other—affiliates 870 3,477 Total coal, hard mineral royalty and other (including affilaites) $ 6,964 $ 4,540 (1) See "Note 16. Subsequent Events" for description of agreements entered into in April 2016 that resulted in lessee forfeitures of ability to recoup previously paid minimums.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The following represents material events that have occurred subsequent to March 31, 2016 through the time of the Partnership’s filing of its Quarterly Report on Form 10-Q with the SEC: Distribution Declared On April 20, 2016 the Board of Directors of GP Natural Resource Partners LLC declared a distribution of $0.45 per unit to be paid by the Partnership on May 13, 2016 to unitholders of record on May 5, 2016. Lease Modifications, Termination and Forfeitures of Minimum Royalty Balances In April 2016, the Partnership entered into agreements with certain lessees to either modify or terminate existing coal related leases that resulted in the Partnership recognizing approximately $35 million of deferred revenue in April 2016 as follows: • An agreement that terminated a central Appalachia coal royalty lease and resulted in the lessee forfeiting the right to recoup $26.2 million of minimum royalties previously paid to the Partnership. The Partnership agreed to transfer its coal mineral rights that were subject to this former lease to the lessee. This terminated lease had no current or planned production and the mineral rights transferred had zero net book value on the Partnership's consolidated Balance Sheets as of March 31, 2016. As a result of this transaction, in April 2016 the Partnership will recognize $26.2 million of revenue. • Lease modifications of existing coal royalty leases resulted in lessee forfeiture of rights to recoup previously paid minimum royalties and the reduction in lessee recoupment time. As a result of these modifications, in April 2016 the Partnership will recognize approximately $9 million of revenue.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Principles of Consolidation and Reporting	Principles of Consolidation and Reporting The accompanying unaudited Consolidated Financial Statements of the Partnership have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") for interim financial information and with Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. As described in "Note 2. Segment Information", we recasted certain prior period amounts to conform to the way we internally manage and monitor segment performance. In particular, prior year general and administrative charges that were allocated to operating segments have been reclassified to Operating and maintenance expenses and Operating and maintenance expenses—affiliates on the Consolidated Statements of Comprehensive Income. The prior period reclassifications for new segments had no impact on the Partnership's consolidated financial position, net income (loss) or cash flows. On January 1, 2016, the Partnership adopted a new accounting standard using a retrospective approach that required the presentation of the Partnership's debt issuance costs as a direct deduction from the related debt liability, rather than recorded as an asset. The adoption resulted in a reclassification that reduced other current assets and short-term debt by $0.2 million and reduced other assets and long-term debt (including affiliate) by $13.8 million on the Partnership’s Consolidated Balance Sheet at December 31, 2015. In our opinion, all adjustments, consisting only of normal recurring adjustments necessary for a fair presentation, have been included. The interim financial statements should be read in conjunction with the audited financial statements and related notes included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2015. Interim results are not necessarily indicative of the results for a full year.
Reverse Unit Split	Reverse Unit Split On January 26, 2016, the board of directors of our general partner approved a 1-for-10 reverse split on our common units, effective following market close on February 17, 2016. Pursuant to the authorization provided, the Partnership completed the 1-for-10 reverse unit split and its common units began trading on a reverse unit split-adjusted basis on the New York Stock Exchange on February 18, 2016. As a result of the reverse unit split, every 10 outstanding common units were combined into one common unit. The reverse unit split reduced the number of common units outstanding from 122.3 million units to 12.2 million units. All unit and per unit data included in these consolidated financial statements has been retroactively restated to reflect the reverse unit split.
Recently Issued Accounting Standards Not Yet Adopted	Recently Issued Accounting Standards Not Yet Adopted In May 2014, the Financial Accounting Standards Board ("FASB") amended its guidance on revenue recognition. The core principle of this amendment is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted for reporting periods beginning after December 15, 2016, including interim reporting periods within that period. This guidance can be adopted either retrospectively to each prior reporting period presented or as a cumulative-effect adjustment as of the date of adoption. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows. In August 2014, the FASB issued guidance on management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The guidance is effective for interim and annual periods ending after December 15, 2016 and early adoption is permitted. The new guidance will require a formal assessment of going concern by management based on criteria prescribed in the new guidance, but will not impact the Partnership's financial position or results of operations. The Partnership is reviewing its policies and processes to ensure compliance with this new guidance. In July 2015, the FASB issued authoritative guidance which intended to simplify the measurement of inventory. This guidance requires an entity to measure inventory at the lower of cost or net realizable value. The amendments do not apply to inventory that is measured using last-in, first-out or the retail inventory method. This guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, with early adoption permitted. This guidance should be applied on a prospective basis. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows. In February 2016, the FASB issued authoritative lease guidance that establishes a right-of-use ("ROU") model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. The main difference between the current requirement under GAAP and the ROU model is the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial position, results of operations and cash flows.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table summarizes certain financial information for each of the Partnership's operating segments (in thousands): Operating Segments For the Three Months Ended Coal, Hard Mineral Royalty and Other Soda Ash VantaCore Oil and Gas Corporate and Financing Total For the three months ended March 31, 2016 Revenues (including affiliates) $ 39,045 $ 9,801 $ 24,682 $ 7,298 $ — $ 80,826 Intersegment revenues (expenses) 21 — (21 ) — — — Gain on asset sales 1,590 — — 20,335 — 21,925 Operating and maintenance expenses (including affiliates) 7,380 — 22,156 5,114 — 34,650 Depreciation, depletion and amortization 6,762 — 3,562 4,419 — 14,743 Asset impairment 1,893 — — 137 — 2,030 Interest expense, net — — — — (23,729 ) (23,729 ) Net income (loss) 24,600 9,801 (1,036 ) 17,963 (27,901 ) 23,427 For the three months ended March 31, 2015 Revenues (including affiliates) $ 53,510 $ 12,523 $ 26,799 $ 14,779 $ — $ 107,611 Gain on asset sales 1,615 — — 451 — 2,066 Operating and maintenance expenses (including affiliates) 8,414 — 25,434 6,649 — 40,497 Depreciation, depletion and amortization 10,016 — 3,856 11,520 — 25,392 Interest expense, net — — — — (22,928 ) (22,928 ) Net income (loss) 36,695 12,523 (2,491 ) (2,939 ) (26,299 ) 17,489 Total assets March 31, 2016 1,016,827 258,939 196,720 132,324 20,083 1,624,893 December 31, 2015 1,047,922 261,942 200,348 158,862 961 1,670,035

Equity Investment (Tables)

Equity Investment (Tables)	3 Months Ended
	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Summarized Financial Information	Our equity in the earnings of Ciner Wyoming is summarized as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Income allocation to NRP’s equity interests $ 10,996 $ 13,727 Amortization of basis difference (1,195 ) (1,204 ) Equity in earnings of unconsolidated investment $ 9,801 $ 12,523 The results of Ciner Wyoming’s operations are summarized as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Sales $ 114,384 $ 120,430 Gross profit 28,251 32,724 Net Income 22,441 28,014 The financial position of Ciner Wyoming is summarized as follows (in thousands): March 31, December 31, (Unaudited) Current assets $ 139,185 $ 144,695 Noncurrent assets 233,236 233,845 Current liabilities 46,881 43,018 Noncurrent liabilities 110,518 116,808

Plant and Equipment (Tables)

Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Plant and Equipment	The Partnership’s plant and equipment consist of the following (in thousands): March 31, December 31, (Unaudited) Plant and equipment at cost $ 77,565 $ 92,203 Construction in process 1,323 1,074 Less accumulated depreciation (21,444 ) (32,038 ) Total plant and equipment, net $ 57,444 $ 61,239

Mineral Rights (Tables)

Mineral Rights (Tables)	3 Months Ended
	Mar. 31, 2016
Extractive Industries [Abstract]
Mineral Rights	The Partnership’s mineral rights consist of the following (in thousands): March 31, 2016 (Unaudited) Carrying Value Accumulated Depletion Net Book Value Coal, Hard Mineral Royalty and Other $ 1,269,633 $ (437,628 ) $ 832,005 VantaCore 112,700 (3,475 ) 109,225 Oil and Gas 136,392 (16,793 ) 119,599 Total $ 1,518,725 $ (457,896 ) $ 1,060,829 December 31, 2015 Carrying Value Accumulated Depletion Net Book Value Coal, Hard Mineral Royalty and Other $ 1,278,274 $ (432,260 ) $ 846,014 VantaCore 112,700 (3,082 ) 109,618 Oil and Gas 155,293 (16,898 ) 138,395 Total $ 1,546,267 $ (452,240 ) $ 1,094,027

Intangible Assets (Including 28

Intangible Assets (Including Affiliate) (Tables)	3 Months Ended
	Mar. 31, 2016
Related Party Transaction [Line Items]
Intangible Assets	The Partnership's intangible assets consist of permits, aggregate-related trade names and other agreements as follows (in thousands): March 31, December 31, (Unaudited) Intangible assets 5,076 5,076 Less accumulated amortization (1,375 ) (1,146 ) Total intangible assets, net $ 3,701 $ 3,930
Affiliated Entity
Related Party Transaction [Line Items]
Intangible Assets	The Partnership's intangible assets—affiliate relate to above market coal transportation contracts with subsidiaries of Foresight Energy LP ("Foresight Energy") in which we receive throughput fees for the handling and transportation of coal. March 31, December 31, (Unaudited) Intangible assets—affiliate $ 81,109 $ 81,109 Less accumulated amortization—affiliate (28,835 ) (28,112 ) Total intangible assets, net—affiliate $ 52,274 $ 52,997

Debt and Debt - Affiliate (Tabl

Debt and Debt - Affiliate (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Long-Term Debt	As of March 31, 2016 and December 31, 2015, debt and debt—affiliate consisted of the following (in thousands): March 31, December 31, (Unaudited) NRP LP debt: 9.125% senior notes, with semi-annual interest payments in April and October, due October 2018, $300 million issued at 99.007% and $125 million issued at 99.5% $ 425,000 $ 425,000 Opco debt (1): $300 million floating rate revolving credit facility, due October 2017 290,000 290,000 4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, due June 2018 13,850 13,850 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2019 64,286 85,714 5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, due July 2020 38,462 38,462 5.31% utility local improvement obligation, with annual principal and interest payments in February, due March 2021 960 1,153 5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, due June 2023 21,600 21,600 4.73% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2023 60,000 60,000 5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 120,000 135,000 8.92% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 36,364 40,909 5.03% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 148,077 148,077 5.18% senior notes, with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 42,308 42,308 NRP Oil and Gas debt: Reserve-based revolving credit facility due November 2019 75,000 85,000 Total debt at face value $ 1,335,907 $ 1,387,073 Net unamortized debt discount (1,889 ) (2,077 ) Net unamortized debt issuance costs (1) (12,683 ) (14,040 ) Total debt, net $ 1,321,335 $ 1,370,956 Less: current portion of long-term debt 154,441 80,745 Total long-term debt $ 1,166,894 $ 1,290,211 (1) See Note 1. " Basis of Presentation" for discussion of debt issuance costs reclassification upon adoption of new accounting standard on January 1, 2016.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Contractual Override, Note Receivable and Long-Term Debt	The following table (in thousands) shows the face and estimated fair values of the Partnership's debt and debt—affiliate: March 31, 2016 December 31, 2015 Debt at Face Value Estimated Fair Value Debt at Face Value Estimated Fair Value (Unaudited) NRP Senior Notes (1) $ 425,000 $ 272,000 $ 425,000 $ 277,313 Opco Senior Notes and utility local improvement obligation (2) 545,907 349,380 587,073 383,065 Opco Revolving Credit Facility (3) 290,000 290,000 290,000 290,000 NRP Oil and Gas RBL Facility (3) 75,000 75,000 85,000 85,000 (1) The Level 1 fair value is based upon quotations obtained for identical instruments on the closing trading prices near period end. (2) The Level 3 fair value is estimated by management using quotations obtained for comparable instruments on the closing trading prices near period end. (3) The Level 3 fair value approximates the carrying amount because the interest rates are variable and reflective of market rates and the terms of the credit facility allow the Partnership to repay this debt at any time without penalty.

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2016
Related Party Transactions [Abstract]
Summary of Reimbursements	Direct general and administrative expenses charged to the Partnership by WPPLP and Quintana Minerals Corporation are as follows (in thousands): Three Months Ended 2016 2015 (Unaudited) Operating and maintenance expenses—affiliates, net $ 2,776 $ 2,702 General and administrative—affiliates 937 1,084

Unit-Based Compensation (Tables

Unit-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Activity in Outstanding Grants	A summary of activity in the outstanding grants during 2016 is as follows (in thousands): Phantom Units Outstanding grants at January 1, 2016 126 Grants during the period — Grants vested and paid during the period (28 ) Forfeitures during the period (3 ) Outstanding grants at March 31, 2016 95

Cash Distributions (Tables)

Cash Distributions (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Schedule of distributions paid	The following table shows the distributions paid by the Partnership during the three months ended March 31, 2016 and 2015: Total Distributions (In thousands) Date Paid Period Covered by Distribution Distribution per Common Unit Common Units GP Interest Total 2016 February 12, 2016 October 1 - December 31, 2015 $ 0.45 $ 5,503 $ 113 $ 5,616 2015 February 13, 2015 October 1 - December 31, 2014 $ 3.50 $ 42,804 $ 874 $ 43,678

Supplementary Unrestricted Su34

Supplementary Unrestricted Subsidiary Information (Tables)	3 Months Ended
	Mar. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheet	CONDENSED CONSOLIDATING BALANCE SHEETS (in thousands) March 31, 2016 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Eliminations Total ASSETS Current assets (including affiliates) $ 10,101 $ 109,133 $ (217 ) $ 119,017 Mineral rights, net 131,905 928,924 — 1,060,829 Equity in unconsolidated investment — 258,939 — 258,939 Other non-current assets (including affiliates) 734 185,374 — 186,108 Total assets $ 142,740 $ 1,482,370 $ (217 ) $ 1,624,893 LIABILITIES AND CAPITAL Current portion of long-term debt, net $ 73,696 $ 80,745 $ — $ 154,441 Other current liabilities (including affiliates) 6,217 42,636 (27 ) 48,826 Long-term debt, net (including affiliate) — 1,166,894 — 1,166,894 Other non-current liabilities (including affiliates) 4,778 159,679 — 164,457 Partners' capital 61,494 32,365 (190 ) 93,669 Non-controlling interest (3,445 ) 51 — (3,394 ) Total liabilities and capital $ 142,740 $ 1,482,370 $ (217 ) $ 1,624,893 December 31, 2015 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Eliminations Total ASSETS Current assets (including affiliates) $ 21,540 $ 100,178 $ (589 ) $ 121,129 Mineral rights, net 134,445 959,582 — 1,094,027 Equity in unconsolidated investment — 261,942 — 261,942 Other non-current assets (including affiliates) (1) 887 192,050 — 192,937 Total assets $ 156,872 $ 1,513,752 $ (589 ) $ 1,670,035 LIABILITIES AND CAPITAL Current portion of long-term debt, net (1) $ — $ 80,745 $ — $ 80,745 Other current liabilities (including affiliates) 7,351 48,356 (43 ) 55,664 Long-term debt, net (including affiliate) (1) 83,600 1,206,611 — 1,290,211 Other non-current liabilities (including affiliates) 4,703 165,770 — 170,473 Partners' capital 64,663 12,219 (546 ) 76,336 Non-controlling interest (3,445 ) 51 — (3,394 ) Total liabilities and capital $ 156,872 $ 1,513,752 $ (589 ) $ 1,670,035
Condensed Income Statement	CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (in thousands) Three Months Ended March 31, 2016 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Total Revenues $ 7,323 $ 95,428 $ 102,751 Operating expenses 9,401 46,194 55,595 Income (loss) from operations (2,078 ) 49,234 47,156 Other expense, net 1,090 22,639 23,729 Net income (loss) (3,168 ) 26,595 23,427 Add: comprehensive loss from unconsolidated investment and other — (545 ) (545 ) Comprehensive income (loss) $ (3,168 ) $ 26,050 $ 22,882 Three Months Ended March 31, 2015 Unrestricted Subsidiaries of NRP NRP and its Restricted Subsidiaries Total Revenues $ 14,900 $ 94,777 $ 109,677 Operating expenses 16,748 52,512 69,260 Income (loss) from operations (1,848 ) 42,265 40,417 Other expense, net 808 22,120 22,928 Net income (loss) (2,656 ) 20,145 17,489 Add: comprehensive loss from unconsolidated investment and other — (965 ) (965 ) Comprehensive income (loss) $ (2,656 ) $ 19,180 $ 16,524

Deferred Revenue and Deferred35

Deferred Revenue and Deferred Revenue - Affiliate (Tables)	3 Months Ended
	Mar. 31, 2016
Deferred Revenue Disclosure [Abstract]
Schedule of Deferred Revenue	The Partnership’s deferred revenue (including affiliate) consist of the following (in thousands): March 31, December 31, (Unaudited) Deferred revenue $ 76,750 $ 80,812 Deferred revenue—affiliate 81,868 82,853 Total deferred revenue (including affiliate) $ 158,618 $ 163,665 The Partnership recognized the following amounts of deferred revenue (including affiliate) attributable to previously paid minimums as Coal, hard mineral royalty and other revenue (in thousands): Three Months Ended 2016 2015 (Unaudited) Coal, hard mineral royalty and other (1) $ 6,094 $ 1,063 Coal, hard mineral royalty and other—affiliates 870 3,477 Total coal, hard mineral royalty and other (including affilaites) $ 6,964 $ 4,540 (1) See "Note 16. Subsequent Events" for description of agreements entered into in April 2016 that resulted in lessee forfeitures of ability to recoup previously paid minimums.

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) shares in Millions	Feb. 18, 2016shares	Mar. 31, 2016USD ($)shares	Oct. 31, 2014USD ($)	Sep. 30, 2013USD ($)	Mar. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Feb. 17, 2016shares
Schedule Of Significant Accounting Policies [Line Items]
Deferred issuance costs		$ 12,683,000			$ 12,683,000	$ 14,040,000
Total debt		$ 1,321,335,000			$ 1,321,335,000	$ 1,370,956,000
Common units outstanding (in shares) | shares	12.2	12.2			12.2	12.2	122.3
NRP LP
Schedule Of Significant Accounting Policies [Line Items]
Rate of senior notes (percent)				9.125%
Repayment of principal amount			$ 122,600,000
NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Schedule Of Significant Accounting Policies [Line Items]
Debt Instrument, face amount		$ 425,000,000			$ 425,000,000
Rate of senior notes (percent)		9.125%			9.125%
Opco
Schedule Of Significant Accounting Policies [Line Items]
Ratio of Indebtedness					4
Leverage ratio		3.09			3.09
Repayment of principal amount				$ 289,000,000
Opco | $300 million floating rate revolving credit facility, due October 2017
Schedule Of Significant Accounting Policies [Line Items]
Total debt		$ 290,000,000			$ 290,000,000
Opco | Senior Notes
Schedule Of Significant Accounting Policies [Line Items]
Total debt		$ 544,900,000			$ 544,900,000
NRP Oil and Gas
Schedule Of Significant Accounting Policies [Line Items]
Leverage ratio		3.10			3.10
Revolving Credit Facility | NRP Oil and Gas
Schedule Of Significant Accounting Policies [Line Items]
Borrowings outstanding		$ 75,000,000			$ 75,000,000	$ 85,000,000
Repayment of principal amount		10,000,000				25,000,000
Reduction in borrowing capacity		$ (13,000,000)			$ (13,000,000)
Common Unitholders
Schedule Of Significant Accounting Policies [Line Items]
Reverse split ratio, common units	0.1
Maximum | Revolving Credit Facility | Opco
Schedule Of Significant Accounting Policies [Line Items]
Ratio of Indebtedness					4
Maximum | Revolving Credit Facility | Opco | Fiscal Quarter Ending on or Before March 31, 2017
Schedule Of Significant Accounting Policies [Line Items]
Ratio of Indebtedness					3.75
Maximum | Revolving Credit Facility | Opco | Fiscal Quarter Ending on or After June 30, 2017
Schedule Of Significant Accounting Policies [Line Items]
Ratio of Indebtedness					3.5
Short-term Debt | Accounting Standards Update 2015-03
Schedule Of Significant Accounting Policies [Line Items]
Deferred issuance costs						(200,000)
Other Current Assets | Accounting Standards Update 2015-03
Schedule Of Significant Accounting Policies [Line Items]
Deferred issuance costs						(200,000)
Other Noncurrent Assets | Accounting Standards Update 2015-03
Schedule Of Significant Accounting Policies [Line Items]
Deferred issuance costs						(13,800,000)
Long-term Debt | Accounting Standards Update 2015-03
Schedule Of Significant Accounting Policies [Line Items]
Deferred issuance costs						$ (13,800,000)

Segment Information - Additiona

Segment Information - Additional Information (Details)	Feb. 01, 2016operation	Feb. 29, 2016operation	Mar. 31, 2016segment
Segment Reporting Information [Line Items]
Number of operating segments | segment			4
Ciner Wyoming
Segment Reporting Information [Line Items]
Percentage of partnership interest owned (percent)			49.00%
Texas, Georgia, Tennessee
Segment Reporting Information [Line Items]
Disposition of reserves and related royalty rights, number of operations | operation	3	3

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 80,826	$ 107,611
Gain on asset sales	21,925	2,066
Operating and maintenance expenses (including affiliates)	34,650	40,497
Depreciation, depletion and amortization	14,743	25,392
Asset impairment	2,030	0
Interest expense, net	(23,729)	(22,928)
Net income (loss)	23,427	17,489
Total assets	1,624,893		$ 1,670,035
Corporate and Financing
Segment Reporting Information [Line Items]
Revenues	0	0
Gain on asset sales	0	0
Operating and maintenance expenses (including affiliates)	0	0
Depreciation, depletion and amortization	0	0
Asset impairment	0
Interest expense, net	(23,729)	(22,928)
Net income (loss)	(27,901)	(26,299)
Total assets	20,083		961
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	0
Coal, Hard Mineral Royalty and Other
Segment Reporting Information [Line Items]
Revenues	28,476	34,449
Coal, Hard Mineral Royalty and Other | Operating Segments
Segment Reporting Information [Line Items]
Revenues	39,045	53,510
Gain on asset sales	1,590	1,615
Operating and maintenance expenses (including affiliates)	7,380	8,414
Depreciation, depletion and amortization	6,762	10,016
Asset impairment	1,893
Interest expense, net	0	0
Net income (loss)	24,600	36,695
Total assets	1,016,827		1,047,922
Coal, Hard Mineral Royalty and Other | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	21
Soda Ash
Segment Reporting Information [Line Items]
Revenues	9,801	12,523
Soda Ash | Operating Segments
Segment Reporting Information [Line Items]
Revenues	9,801	12,523
Gain on asset sales	0	0
Operating and maintenance expenses (including affiliates)	0	0
Depreciation, depletion and amortization	0	0
Asset impairment	0
Interest expense, net	0	0
Net income (loss)	9,801	12,523
Total assets	258,939		261,942
Soda Ash | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	0
VantaCore
Segment Reporting Information [Line Items]
Revenues	24,682	26,799
VantaCore | Operating Segments
Segment Reporting Information [Line Items]
Revenues	24,682	26,799
Gain on asset sales	0	0
Operating and maintenance expenses (including affiliates)	22,156	25,434
Depreciation, depletion and amortization	3,562	3,856
Asset impairment	0
Interest expense, net	0	0
Net income (loss)	(1,036)	(2,491)
Total assets	196,720		200,348
VantaCore | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	(21)
Oil and Gas
Segment Reporting Information [Line Items]
Revenues	7,298	14,779
Oil and Gas | Operating Segments
Segment Reporting Information [Line Items]
Revenues	7,298	14,779
Gain on asset sales	20,335	451
Operating and maintenance expenses (including affiliates)	5,114	6,649
Depreciation, depletion and amortization	4,419	11,520
Asset impairment	137
Interest expense, net	0	0
Net income (loss)	17,963	$ (2,939)
Total assets	132,324		$ 158,862
Oil and Gas | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	$ 0

Equity Investment - Additional

Equity Investment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Distributions from equity method Investment	$ 12,250	$ 10,903
Weighted average useful life of assets (in years)	28 years
Ciner Wyoming
Schedule of Equity Method Investments [Line Items]
Percentage of partnership interest owned (percent)	49.00%
Distributions from equity method Investment	$ 12,300	10,900
Increase in fair value of property, plant and equipment	153,600			$ 154,800
Anadarko Holding Company [Member] | Ciner Wyoming
Schedule of Equity Method Investments [Line Items]
Equity Investment Contingent Consideration Paid	$ 7,200	$ 3,800	$ 500

Equity Investment - Schedule o

Equity Investment - Schedule of Summarized Financial Information of Unaudited Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Net income	$ 23,427	$ 17,489
Current assets	119,017		$ 121,129
Current liabilities	203,267		136,409
Ciner Wyoming
Schedule of Equity Method Investments [Line Items]
Income allocation to NRP’s equity interests	10,996	13,727
Amortization of basis difference	(1,195)	(1,204)
Equity in earnings of unconsolidated investment	9,801	12,523
Sales	114,384	120,430
Gross profit	28,251	32,724
Net income	22,441	$ 28,014
Current assets	139,185		144,695
Noncurrent assets	233,236		233,845
Current liabilities	46,881		43,018
Noncurrent liabilities	$ 110,518		$ 116,808

Plant and Equipment - Plant and

Plant and Equipment - Plant and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Plant and equipment at cost	$ 77,565	$ 92,203
Construction in process	1,323	1,074
Less accumulated depreciation	(21,444)	(32,038)
Total plant and equipment, net	$ 57,444	$ 61,239

Plant and Equipment - Additiona

Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense on plant and equipment	$ 3.4	$ 4.5

Mineral Rights - Mineral Rights

Mineral Rights - Mineral Rights (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	$ 1,518,725	$ 1,546,267
Accumulated Depletion	(457,896)	(452,240)
Net Book Value	1,060,829	1,094,027
Coal, Hard Mineral Royalty and Other
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	1,269,633	1,278,274
Accumulated Depletion	(437,628)	(432,260)
Net Book Value	832,005	846,014
VantaCore
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	112,700	112,700
Accumulated Depletion	(3,475)	(3,082)
Net Book Value	109,225	109,618
Oil and Gas
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	136,392	155,293
Accumulated Depletion	(16,793)	(16,898)
Net Book Value	$ 119,599	$ 138,395

Mineral Rights - Additional Inf

Mineral Rights - Additional Information (Detail) $ in Thousands	Feb. 01, 2016USD ($)operation	Feb. 29, 2016operation	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Total depletion and amortization expense on mineral interests			$ 10,300	$ 19,900
Proceeds from sale of oil and gas properties			32,848	3,395
Gain on asset sales			21,925	$ 2,066
Appalachian Basin
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Proceeds from sale of oil and gas properties			37,500
Gain on asset sales			20,300
Texas, Georgia, Tennessee
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Gain on asset sales			$ 1,600
Disposition of reserves and related royalty rights, number of operations | operation	3	3
Proceeds from sale of hard mineral reserves	$ 10,000

Intangible Assets (Including 45

Intangible Assets (Including Affiliate) - Intangible Assets - Affiliate (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Intangible assets	$ 5,076	$ 5,076
Less accumulated amortization	(1,375)	(1,146)
Total intangible assets, net	3,701	3,930
Affiliated Entity
Related Party Transaction [Line Items]
Intangible assets	81,109	81,109
Less accumulated amortization	(28,835)	(28,112)
Total intangible assets, net	$ 52,274	$ 52,997

Intangible Assets (Including 46

Intangible Assets (Including Affiliate) - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	$ 5,076	$ 5,076
Less accumulated amortization	(1,375)	(1,146)
Total intangible assets, net	$ 3,701	$ 3,930

Intangible Assets (Including 47

Intangible Assets (Including Affiliate) - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Related Party Transaction [Line Items]
Amortization expense—affiliate	$ 0.2	$ 0.2
Affiliated Entity
Related Party Transaction [Line Items]
Amortization expense—affiliate	$ 0.7	$ 0.8

Debt and Debt - Affiliate - Lon

Debt and Debt - Affiliate - Long-Term Debt (Detail) - USD ($)	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Oct. 31, 2014	Sep. 30, 2013
Debt Instrument [Line Items]
Debt at Face Value	$ 1,335,907,000	$ 1,387,073,000
Net unamortized debt discount	(1,889,000)	(2,077,000)
Net unamortized debt issuance costs	(12,683,000)	(14,040,000)
Total debt	1,321,335,000	1,370,956,000
Less - current portion of long term debt	(154,441,000)	(80,745,000)
Long Term Debt And Debt Affiliate Noncurrent	$ 1,166,894,000	1,290,211,000
NRP LP
Debt Instrument [Line Items]
Rate of senior notes (percent)					9.125%
Floating rate revolving credit facility				$ 125,000,000	$ 300,000,000
Senior Note issue percentage				99.50%	99.007%
NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Rate of senior notes (percent)	9.125%
Debt Instrument, face amount	$ 425,000,000
Debt at Face Value	425,000,000	425,000,000
Opco | $300 million floating rate revolving credit facility, due October 2017
Debt Instrument [Line Items]
Floating rate revolving credit facility	300,000,000		$ 300,000,000
Debt at Face Value	290,000,000	290,000,000
Total debt	$ 290,000,000
Opco | 4.91% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2018
Debt Instrument [Line Items]
Rate of senior notes (percent)	4.91%
Debt at Face Value	$ 13,850,000	13,850,000
Opco | 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019
Debt Instrument [Line Items]
Rate of senior notes (percent)	8.38%
Debt at Face Value	$ 64,286,000	85,714,000
Opco | 5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.05%
Debt at Face Value	$ 38,462,000	38,462,000
Opco | 5.31% utility local improvement obligation, with annual principal and interest payments, maturing in March 2021
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.31%
Debt at Face Value	$ 960,000	1,153,000
Opco | 5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.55%
Debt at Face Value	$ 21,600,000	21,600,000
Opco | 4.73% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2023
Debt Instrument [Line Items]
Rate of senior notes (percent)	4.73%
Debt at Face Value	$ 60,000,000	60,000,000
Opco | 5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.82%
Debt at Face Value	$ 120,000,000	135,000,000
Opco | 8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024
Debt Instrument [Line Items]
Rate of senior notes (percent)	8.92%
Debt at Face Value	$ 36,364,000	40,909,000
Opco | 5.03% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.03%
Debt at Face Value	$ 148,077,000	148,077,000
Opco | 5.18% senior notes, with semi-annual interest payments in June and December, with scheduled principal payments beginning December 2014, maturing in December 2026
Debt Instrument [Line Items]
Rate of senior notes (percent)	5.18%
Debt at Face Value	$ 42,308,000	42,308,000
NRP Oil and Gas | Reserve Based Revolving Credit Facility Due 2019
Debt Instrument [Line Items]
Debt at Face Value	75,000,000	$ 85,000,000
Senior Notes Offering Price One [Member] | NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Floating rate revolving credit facility	$ 300,000,000
Senior Note issue percentage	99.007%
Senior Notes Offering Price Two [Member] | NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Floating rate revolving credit facility	$ 125,000,000
Senior Note issue percentage	99.50%

Debt and Debt - Affiliate - Add

Debt and Debt - Affiliate - Additional Information (Detail)	Jun. 30, 2016	Mar. 31, 2016USD ($)	Mar. 31, 2016USD ($)	Jun. 30, 2015USD ($)	Oct. 31, 2014USD ($)	Sep. 30, 2013USD ($)	Aug. 31, 2013USD ($)	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)	Oct. 01, 2016USD ($)	Aug. 01, 2016USD ($)	Oct. 31, 2015USD ($)	Apr. 30, 2015USD ($)	Nov. 30, 2014USD ($)
Debt Instrument [Line Items]
Principal balance		$ 1,335,907,000	$ 1,335,907,000					$ 1,335,907,000		$ 1,387,073,000
Ciner Wyoming
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)		49.00%	49.00%					49.00%
Ciner Wyoming | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)		49.00%	49.00%					49.00%
NRP LP
Debt Instrument [Line Items]
Rate of senior notes (percent)						9.125%
Floating rate revolving credit facility					$ 125,000,000	$ 300,000,000
Senior Note issue percentage					99.50%	99.007%
Repayment of principal amount					$ 122,600,000
NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Rate of senior notes (percent)		9.125%	9.125%					9.125%
Debt Instrument, face amount		$ 425,000,000	$ 425,000,000					$ 425,000,000
Principal balance		$ 425,000,000	$ 425,000,000					$ 425,000,000		425,000,000
NRP LP | Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio		1	1					1
NRP LP | Maximum
Debt Instrument [Line Items]
Fixed charge coverage ratio		2	2					2
Opco
Debt Instrument [Line Items]
Repayment of principal amount						$ 289,000,000
Fixed charge coverage ratio		5.43	5.43					5.43
Ratio of Indebtedness								4
Ratio of consolidated EBITDDA to consolidated fixed charges								3.5
Percentage of consolidated net tangible assets debt of subsidiaries not permitted to exceed								10.00%
Leverage ratio		3.09	3.09					3.09
Opco | Revolving Credit Facility
Debt Instrument [Line Items]
Weighted average interest rate (percent)		3.80%	3.80%					3.80%	1.94%
Commitment fee on the unused portion of the borrowing base under the credit facility (percent)								0.50%
Ratio of consolidated EBITDDA to consolidated fixed charges								3.5
Secured Debt		$ 698,100,000	$ 698,100,000					$ 698,100,000		709,900,000
Opco | $300 million floating rate revolving credit facility, due October 2017
Debt Instrument [Line Items]
Floating rate revolving credit facility		300,000,000	300,000,000	$ 300,000,000				300,000,000
Principal balance		$ 290,000,000	$ 290,000,000					$ 290,000,000		290,000,000
Opco | $300 million floating rate revolving credit facility, due October 2017 | Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit facility maturity date				Oct. 2, 2017
Opco | $300 million floating rate revolving credit facility, due August 2016
Debt Instrument [Line Items]
Floating rate revolving credit facility				$ 300,000,000
Opco | 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019
Debt Instrument [Line Items]
Rate of senior notes (percent)		8.38%	8.38%					8.38%
Principal balance		$ 64,286,000	$ 64,286,000					$ 64,286,000		85,714,000
Opco | 8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024
Debt Instrument [Line Items]
Rate of senior notes (percent)		8.92%	8.92%					8.92%
Principal balance		$ 36,364,000	$ 36,364,000					$ 36,364,000		40,909,000
Opco | Senior Notes
Debt Instrument [Line Items]
Principal balance		$ 544,900,000	$ 544,900,000					544,900,000		$ 585,900,000
Principal payments on its senior notes								$ 41,000,000	$ 41,000,000
Partnership leverage ratio								3.75
Additional interest accrue		2.00%	2.00%					2.00%
Opco | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Ratio of Indebtedness								4
Opco | Fiscal Quarter Ending on or Before March 31, 2017 | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Ratio of Indebtedness								3.75
Opco | Fiscal Quarter Ending on or After June 30, 2017 | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Ratio of Indebtedness								3.5
Opco | Federal Funds Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)				0.50%				0.50%
Opco | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)				1.00%				1.00%
Opco | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility, Basis Spread Condition One | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				2.375%
Opco | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility, Basis Spread Condition Two | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				3.375%
Opco | London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility, Basis Spread Condition One | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)								1.50%
Opco | London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility, Basis Spread Condition Two | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)								2.50%
Opco | London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility, Basis Spread Condition One | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)								2.50%
Opco | London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility, Basis Spread Condition Two | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)								3.50%
NRP Oil and Gas
Debt Instrument [Line Items]
Leverage ratio, maximum		4								3.5
Leverage ratio, remainder of the term			3.5
Current ratio, minimum		0.75								1
Minimum current ratio, remainder of term			1
Leverage ratio		3.10	3.10					3.10
Current ratio		1.94	1.94					1.94
NRP Oil and Gas | Revolving Credit Facility
Debt Instrument [Line Items]
Floating rate revolving credit facility														$ 105,000,000
Repayment of principal amount			$ 10,000,000							$ 25,000,000
Commitment fee on the unused portion of the borrowing base under the credit facility (percent)			0.50%
Borrowings outstanding		$ 75,000,000	$ 75,000,000					$ 75,000,000		$ 85,000,000
Term of credit facility							5 years
Senior secured revolving credit facility							$ 100,000,000
Maximum increase in aggregate commitment		$ 75,000,000	$ 75,000,000					$ 75,000,000					$ 88,000,000	$ 105,000,000	$ 137,000,000
Debt Instrument maturities date								2019-11
NRP Oil and Gas | Amended On November 2014 | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum increase in aggregate commitment															$ 500,000,000
NRP Oil and Gas | Forecast
Debt Instrument [Line Items]
Leverage ratio, maximum	4.5
Current ratio, minimum	0.75
NRP Oil and Gas | Forecast | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum increase in aggregate commitment											$ 50,000,000	$ 70,000,000
NRP Oil and Gas | Federal Funds Rate | Revolving Credit Facility, Basis Spread Condition One | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)								0.50%
NRP Oil and Gas | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility, Basis Spread Condition One | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)								4.00%
NRP Oil and Gas | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility, Basis Spread Condition Two | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)								4.00%

Fair Value Measurements - Contr

Fair Value Measurements - Contractual Override, Note Receivable and Long-Term Debt (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at Face Value	$ 1,335,907	$ 1,387,073
Opco Revolving Credit Facility And Term Loan Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at Face Value	290,000	290,000
Estimated Fair Value	290,000	290,000
Nrp Oil And Gas Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at Face Value	75,000	85,000
Estimated Fair Value	75,000	85,000
Nrp Lp Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at Face Value	425,000	425,000
Estimated Fair Value	272,000	277,313
Opco Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at Face Value	545,907	587,073
Estimated Fair Value	349,380	383,065
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contracts receivable—affiliate, current and long-term	$ 3,700	$ 4,200

Related Party Transactions - Su

Related Party Transactions - Summary of Reimbursements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	$ 3,748	$ 3,076
General and administrative—affiliates	937	1,084
Affiliated Entity | Western Pocahontas Properties and Quintana Minerals Corporation
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	2,776	2,702
General and administrative—affiliates	$ 937	$ 1,084

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) shares in Thousands	1 Months Ended	3 Months Ended
	Oct. 31, 2014	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Related Party Transaction [Line Items]
Amount payable to related parties		$ 1,227,000		$ 1,464,000
Revenues		80,826,000	$ 107,611,000
Deferred revenue—affiliates		81,868,000		82,853,000
Accounts receivable		7,525,000		6,864,000
Operating and maintenance expenses—affiliates, net		3,748,000	3,076,000
Quintana Minerals
Related Party Transaction [Line Items]
Amount payable to related parties		600,000		1,100,000
Western Pocahontas Properties
Related Party Transaction [Line Items]
Amount payable to related parties		$ 600,000		300,000
Cline Affiliates
Related Party Transaction [Line Items]
Rate of interest in the partnerships general partner (percent)		31.00%
Related party transaction number of units hold by the related party in partnerships' general partner (in shares)		500
Accounts receivable		$ 7,400,000		6,400,000
Net amount receivable				4,900,000
Accounts receivable				1,500,000
Cline Affiliates
Related Party Transaction [Line Items]
Deferred revenue—affiliates		81,600,000		82,600,000
Net amount receivable		4,500,000
Accounts receivable		2,200,000
Foresight Energy Lp | Coal Sales
Related Party Transaction [Line Items]
Revenues		10,100,000	18,300,000
Sugar Camp
Related Party Transaction [Line Items]
Contracts receivable—affiliate, current and long-term		80,200,000		81,200,000
Unearned income		34,500,000		35,400,000
Net amount receivable		45,700,000		45,900,000
Accounts receivable		2,100,000		2,000,000
Corsa
Related Party Transaction [Line Items]
Deferred revenue—affiliates		300,000		300,000
Accounts receivable		100,000		200,000
Royalty Revenue from Coal		500,000	800,000
Western Pocahontas Properties Limited Partnership | Affiliated Entity
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net		600,000	$ 0
Other assets—affiliate		$ 500,000		$ 1,100,000
Senior Notes Due 2018 | Cline Trust Company
Related Party Transaction [Line Items]
Partnership common units owned (in shares)		540
Principal amount of partnership purchased	$ 20,000,000	$ 20,000,000
Rate of senior notes (percent)	9.125%	9.125%
Aggregate principal amount of senior notes	$ 125,000,000
Senior notes due		$ 19,900,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Apr. 01, 2016	Mar. 31, 2016
Lawsuit Against Hillsboro Energy LLC
Commitments And Contingencies [Line Items]
Minimum quarterly deficiency payments		$ 7.5
Minimum deficiency payments		30
Loss contingency		$ 23.6
Subsequent Event | Lawsuit Against Macoupin Energy, LLC
Commitments And Contingencies [Line Items]
Damages sought, value	$ 4.7

Major Customers (Details)

Major Customers (Details) - Foresight Energy Lp - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Concentration Risk [Line Items]
Revenues	$ 10.1	$ 18.3
Sales Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk (percent)	9.80%	16.70%

Unit-Based Compensation - Addit

Unit-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of Grants (in years)	4 years
Payments made in connection with Long-Term Incentive Plan	$ 1.5	$ 4.4
Unaccrued cost associated with outstanding grants and related DERs	0.4		$ 0.7
General Partner
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses related to Incentive Plan to be reimbursed to general partner (less than)	$ 0.1	$ 0.1
Phantom Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of Grants (in years)	4 years
Number of trading days (in days)	20 days

Unit-Based Compensation - Summ

Unit-Based Compensation - Summary of Activity in Outstanding Grants (Details)	3 Months Ended
	Mar. 31, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding grants at beginning of period (in shares)	126,000
Grants during the period (in shares)	0
Grants vested and paid during the period (in shares)	(28,000)
Forfeitures during the period (in shares)	(3,000)
Outstanding grants at the end of the period (in shares)	95,000

Cash Distributions (Details)

Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 12, 2016	Feb. 13, 2015	Mar. 31, 2016	Mar. 31, 2015
Equity [Abstract]
Distribution per common unit (in dollars per share)	$ 0.45	$ 3.50
Distributions paid to common unitholders'	$ 5,503	$ 42,804	$ 5,616	$ 43,678
Distributions paid to general partners	113	874
Total distributions paid	$ 5,616	$ 43,678	$ 5,616

Supplementary Unrestricted Su58

Supplementary Unrestricted Subsidiary Information - CONDENSED CONSOLIDATING BALANCE SHEETS (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
ASSETS
Current assets (including affiliates)	$ 119,017	$ 121,129
Mineral rights, net	1,060,829	1,094,027
Equity in unconsolidated investment	258,939	261,942
Other non-current assets (including affiliates)	186,108	192,937
Total assets	1,624,893	1,670,035
LIABILITIES AND CAPITAL
Current portion of long-term debt, net	154,441	80,745
Other current liabilities (including affiliates)	48,826	55,664
Long-term debt, net (including affiliate)	1,166,894	1,290,211
Other non-current liabilities (including affiliates)	164,457	170,473
Partners' capital	93,669	76,336
Non-controlling interest	(3,394)	(3,394)
Total liabilities and capital	1,624,893	1,670,035
Consolidation, Eliminations
ASSETS
Current assets (including affiliates)	(217)	(589)
Mineral rights, net	0	0
Equity in unconsolidated investment	0	0
Other non-current assets (including affiliates)	0	0
Total assets	(217)	(589)
LIABILITIES AND CAPITAL
Current portion of long-term debt, net	0	0
Other current liabilities (including affiliates)	(27)	(43)
Long-term debt, net (including affiliate)	0	0
Other non-current liabilities (including affiliates)	0	0
Partners' capital	(190)	(546)
Non-controlling interest	0	0
Total liabilities and capital	(217)	(589)
Unrestricted Subsidiaries of NRP
ASSETS
Current assets (including affiliates)	10,101	21,540
Mineral rights, net	131,905	134,445
Equity in unconsolidated investment	0	0
Other non-current assets (including affiliates)	734	887
Total assets	142,740	156,872
LIABILITIES AND CAPITAL
Current portion of long-term debt, net	73,696	0
Other current liabilities (including affiliates)	6,217	7,351
Long-term debt, net (including affiliate)	0	83,600
Other non-current liabilities (including affiliates)	4,778	4,703
Partners' capital	61,494	64,663
Non-controlling interest	(3,445)	(3,445)
Total liabilities and capital	142,740	156,872
NRP and its Restricted Subsidiaries
ASSETS
Current assets (including affiliates)	109,133	100,178
Mineral rights, net	928,924	959,582
Equity in unconsolidated investment	258,939	261,942
Other non-current assets (including affiliates)	185,374	192,050
Total assets	1,482,370	1,513,752
LIABILITIES AND CAPITAL
Current portion of long-term debt, net	80,745	80,745
Other current liabilities (including affiliates)	42,636	48,356
Long-term debt, net (including affiliate)	1,166,894	1,206,611
Other non-current liabilities (including affiliates)	159,679	165,770
Partners' capital	32,365	12,219
Non-controlling interest	51	51
Total liabilities and capital	$ 1,482,370	$ 1,513,752

Supplementary Unrestricted Su59

Supplementary Unrestricted Subsidiary Information - CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed Income Statements, Captions [Line Items]
Revenues	$ 102,751	$ 109,677
Operating expenses	55,595	69,260
Income from operations	47,156	40,417
Other expense, net	23,729	22,928
Net income	23,427	17,489
Add: comprehensive loss from unconsolidated investment and other	(545)	(965)
Comprehensive income	22,882	16,524
Unrestricted Subsidiaries of NRP
Condensed Income Statements, Captions [Line Items]
Revenues	7,323	14,900
Operating expenses	9,401	16,748
Income from operations	(2,078)	(1,848)
Other expense, net	1,090	808
Net income	(3,168)	(2,656)
Add: comprehensive loss from unconsolidated investment and other	0	0
Comprehensive income	(3,168)	(2,656)
NRP and its Restricted Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues	95,428	94,777
Operating expenses	46,194	52,512
Income from operations	49,234	42,265
Other expense, net	22,639	22,120
Net income	26,595	20,145
Add: comprehensive loss from unconsolidated investment and other	(545)	(965)
Comprehensive income	$ 26,050	$ 19,180

Supplementary Unrestricted Su60

Supplementary Unrestricted Subsidiary Information - Additional Information (Details)	Mar. 31, 2016
Brp Llc
Related Party Transaction [Line Items]
Percentage of partnership interest owned (percent)	51.00%

Deferred Revenue and Deferred61

Deferred Revenue and Deferred Revenue - Affiliate - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 76,750		$ 80,812
Deferred revenue—affiliates	81,868		82,853
Total deferred revenue (including affiliate)	158,618		$ 163,665
Coal, Hard Mineral Royalty and Other
Deferred Revenue Arrangement [Line Items]
Deferred revenue recognized	6,094	$ 1,063
Deferred revenue recognized, including related party	6,964	4,540
Coal, Hard Mineral Royalty and Other | Affiliated Entity
Deferred Revenue Arrangement [Line Items]
Deferred revenue recognized	$ 870	$ 3,477

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Apr. 20, 2016	Feb. 12, 2016	Feb. 13, 2015	Apr. 30, 2016
Subsequent Event [Line Items]
Distribution paid (in dollar per share)		$ 0.45	$ 3.50
Subsequent Event
Subsequent Event [Line Items]
Distribution paid (in dollar per share)	$ 0.45
Leasing Arrangement | Subsequent Event
Subsequent Event [Line Items]
Deferred revenue recognized				$ 35
Central Appalachia Coal Royalty Lease Termination | Subsequent Event
Subsequent Event [Line Items]
Deferred revenue recognized				26.2
Lease Modifications of Existing Coal Royalty Leases | Subsequent Event
Subsequent Event [Line Items]
Deferred revenue recognized				$ 9