Natural Resource Partners (NRP) 10-Q 10 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	May 01, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
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	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12,232,006

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 112,945	$ 40,371
Accounts receivable, net	44,470	43,202
Accounts receivable—affiliates	7,605	6,658
Inventory	7,624	6,893
Prepaid expenses and other	4,122	6,137
Current assets of discontinued operations	991	991
Current assets held for sale	17,500	0
Total current assets	195,257	104,252
Land	12,591	25,252
Plant and equipment, net	48,579	49,443
Mineral rights, net	895,071	908,192
Intangible assets, net	3,065	3,236
Intangible assets, net—affiliate	49,043	49,811
Equity in unconsolidated investment	252,803	255,901
Long-term contracts receivable—affiliate	42,619	43,785
Other assets	9,270	3,791
Other assets—affiliate	952	1,018
Total assets	1,509,250	1,444,681
Current liabilities:
Accounts payable	6,538	6,234
Accounts payable—affiliates	1,196	940
Accrued liabilities	33,509	41,587
Current portion of long-term debt, net	263,502	138,903
Current liabilities of discontinued operations	304	353
Total current liabilities	305,049	188,017
Deferred revenue	46,008	44,931
Deferred revenue—affiliates	68,735	71,632
Long-term debt, net	707,424	987,400
Warrant liabilities	61,417	0
Other non-current liabilities	3,102	4,565
Total liabilities	1,191,735	1,296,545
Convertible Preferred Units (250,000 units issued and outstanding at $1,000 par value per unit; liquidation preference of $1,500 per unit)	159,292	0
Partners’ capital:
Common unitholders’ interest (12,232,006 units issued and outstanding)	163,304	152,309
General partner’s interest	1,111	887
Accumulated other comprehensive loss	(2,798)	(1,666)
Total partners’ capital	161,617	151,530
Non-controlling interest	(3,394)	(3,394)
Total capital	158,223	148,136
Total liabilities and capital	$ 1,509,250	$ 1,444,681

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common units issued and outstanding (in shares)	12,232,006	12,232,006
Preferred units issued and outstanding (in shares)	250,000	0
Preferred unit par value per unit	$ 1,000	$ 0
Preferred unit liquidation preference per unit	$ 1,500	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues and other income:
Revenues and other income	$ 88,653	$ 73,901
Gain on asset sales, net	44	21,925
Total revenues and other income	88,697	95,826
Operating expenses:
Operating and maintenance expenses	29,628	26,785
Operating and maintenance expenses—affiliates, net	2,555	3,484
Depreciation, depletion and amortization	9,724	9,780
Amortization expense—affiliate	768	722
General and administrative	6,078	3,235
General and administrative—affiliates	1,124	937
Asset impairments	1,778	1,893
Total operating expenses	51,655	46,836
Income from operations	37,042	48,990
Other income (expense)
Interest expense	(23,141)	(22,196)
Interest expense—affiliate	0	(462)
Debt modification expense	(7,807)	0
Warrant issuance expense	(5,709)	0
Fair value adjustments for warrant liabilities	16,569	0
Interest income	17	19
Other expense, net	(20,071)	(22,639)
Net income from continuing operations	16,971	26,351
Loss from discontinued operations	(207)	(2,924)
Net income	16,764	23,427
Income attributable to preferred unitholders	(2,500)	0
Net income attributable to common unitholders and general partner	$ 14,264	$ 23,427
Basic and diluted net income (loss) per common unit (in dollars per share):
Net income (loss) per common unit from continuing operations (in dollars per share)	$ 1.17	$ 2.12
Net income (loss) per common unit from discontinued operations (in dollars per share)	0.03	2.12
Basic net income per common unit (in dollars per share)	1.15	1.88
Diluted net income per common unit (in dollars per share)	$ 0.02	$ 1.88
Add: comprehensive loss from unconsolidated investment and other	$ (1,132)	$ (545)
Comprehensive income	15,632	22,882
Coal Royalty and Other
Revenues and other income:
Revenues and other income	34,994	28,849
Coal royalty and other—affiliates	16,144	10,569
VantaCore
Revenues and other income:
Revenues and other income	27,221	24,682
Soda Ash
Revenues and other income:
Revenues and other income	$ 10,294	$ 9,801

Consolidated Statements of Part

Consolidated Statements of Partners' Capital - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	General Partner	Common Unitholders	Accumulated Other Comprehensive Income (Loss)	Partners Capital Excluding Noncontrolling Interest	Non-Controlling Interest
Balance, beginning of period (in shares) at Dec. 31, 2016			12,232
Balance, beginning of period at Dec. 31, 2016	$ 148,136	$ 887	$ 152,309	$ (1,666)	$ 151,530	$ (3,394)
Net Income	16,764	266	16,498		16,764
Distributions to unitholders	(5,615)	(112)	$ (5,503)		(5,615)
Non-cash contributions	70	100			70
Comprehensive income from unconsolidated investment and other	(1,132)			(1,132)	(1,132)
Balance, end of period (in shares) at Mar. 31, 2017			12,232
Balance, end of period at Mar. 31, 2017	158,223	$ 1,111	$ 163,304	$ (2,798)	$ 161,617	$ (3,394)
Earnings attributable to Preferred Unitholders	$ 2,500

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Cash Flows [Abstract]
Net income	$ 16,764	$ 23,427
Adjustments to reconcile net income to net cash provided by operating activities of continuing operations:
Depreciation, depletion and amortization	9,724	9,780
Amortization expense—affiliate	768	722
Distributions from equity earnings from unconsolidated investment	12,250	12,250
Equity earnings from unconsolidated investment	(10,294)	(9,801)
Gain on asset sales, net	(44)	(21,925)
Fair value adjustments for Warrant liabilities	(16,569)	0
Debt modification expense	7,807	0
Warrant issuance expense	5,709	0
Loss from discontinued operations	207	2,924
Asset impairments	1,778	1,893
Other, net	1,090	2,266
Other, net—affiliates	887	1,783
Change in operating assets and liabilities:
Accounts receivable	(1,267)	3,955
Accounts receivable—affiliates	(947)	(1,070)
Accounts payable	986	280
Accounts payable—affiliates	256	225
Accrued liabilities	(8,080)	1,274
Accrued liabilities—affiliates	0	457
Deferred revenue	1,077	(4,063)
Deferred revenue—affiliates	(2,897)	(985)
Other items, net	1,284	(704)
Net cash provided by operating activities of continuing operations	20,489	22,688
Net cash provided by (used in) operating activities of discontinued operations	(284)	3,972
Net cash provided by operating activities	20,205	26,660
Cash flows from investing activities:
Proceeds from sale of oil and gas royalty properties	(548)	32,848
Proceeds from sale of coal and aggregates royalty properties	139	9,802
Return of long-term contract receivables—affiliate	414	309
Proceeds from sale of plant and equipment and other	22	3
Acquisition of plant and equipment and other	(2,095)	(1,421)
Net cash provided by (used in) investing activities of continuing operations	(2,068)	41,541
Net cash provided by (used in) investing activities of discontinued operations	29	(2,725)
Net cash provided by (used in) investing activities	(2,039)	38,816
Cash flows from financing activities:
Proceeds from issuance of Convertible Preferred Units and Warrants, net	242,100	0
Proceeds from issuance of 2022 Senior Notes, net	103,688	0
Repayments of loans	(251,010)	(41,166)
Distributions to common unitholders and general partner	(5,615)	(5,616)
Contributions to discontinued operations	(255)	0
Debt issue costs and other	(34,755)	(8,032)
Net cash provided by (used in) financing activities of continuing operations	54,153	(54,814)
Net cash provided by (used in) financing activities of discontinued operations	255	(10,338)
Net cash provided by (used in) financing activities	54,408	(65,152)
Net increase in cash and cash equivalents	72,574	324
Cash and cash equivalents of continuing operations at beginning of period	112,945	50,619
Cash and cash equivalents of discontinued operations at beginning of period	0	10,569
Cash and cash equivalents of discontinued operations at end of period	0	1,478
Cash and cash equivalents at beginning of period	40,371	51,773
Cash and cash equivalents at end of period	112,945	52,097
Cash paid during the period for interest	19,851	13,181
Issuance of 2022 Senior Notes in exchange for 2018 Senior Notes	$ 240,638	$ 0

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	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, construction aggregates 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. In management's opinion, all necessary adjustments to fairly present the Partnership's results of operations, financial position and cash flows for the periods presented have been made and all such adjustments were of a normal and recurring nature. Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. As described in Note 5. Discontinued Operations , the Partnership has classified the assets and liabilities, operating results and cash flows of its non-operated oil and gas working interest assets as discontinued operations in its consolidated financial statements for all periods presented. As described in Note 4. Segment Information , the Partnership has reclassified oil and gas royalty activities in prior period amounts to conform to the way it internally manages and monitors segment performance that had no impact on the Partnership's consolidated financial position, net income or cash flows. In the second quarter of 2016, the Partnership determined its net cash provided by operating and investing activities were understated by $7.2 million and $0.8 million , respectively, and net cash used in financing activities was understated by $8.0 million for the three months ended March 31, 2016. The Consolidated Statement of Cash Flows for the three months ended March 31, 2016 has been corrected for this error. Recently Issued Accounting Standards The FASB issued authoritative guidance on revenue recognition. The core principle of this guidance 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. The guidance will also require enhanced disclosures, provide more comprehensive guidance for transactions such as service revenue and contract modifications, and enhance guidance for multiple-element arrangements. The Partnership is required to adopt this guidance in the first quarter of 2018 using one of two retrospective application methods. The Partnership has performed revenue scoping procedures to identify the contracts for all of its revenue streams and utilized the practical expedient of grouping contracts or performance obligations with similar characteristics as prescribed by the new standard. The Partnership is currently evaluating these contracts; and while the effect of adoption is unknown, it is not currently aware of any material changes that would result from adoption of this new revenue recognition guidance and expects to complete its assessment of how it will be affected in the second quarter of 2017. The Partnership anticipates utilizing the full retrospective adoption method for financial statement comparability and electing the practical expedient of not restating contracts that begin and are completed within the same annual reporting period. The FASB issued authoritative lease guidance that requires lessees to recognize assets and liabilities on the balance sheet for the present value of the rights and obligations created by all leases with terms of more than 12 months. The guidance also requires disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual and interim periods ending after December 31, 2018. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements. The FASB issued authoritative guidance that replaces the incurred loss impairment methodology in the current standard with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The guidance is effective for annual and interim periods ending after December 31, 2019. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements. The FASB issued authoritative guidance to clarify how certain cash receipts and cash payments are presented and classified in the statement of cash flows in order to reduce current and potential future diversity in practice. The guidance is effective for annual and interim periods ending after December 31, 2017. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements.

Convertible Preferred Units and

Convertible Preferred Units and Warrants	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Convertible Preferred Units and Warrants	Convertible Preferred Units and Warrants On March 2, 2017, NRP issued $250 million of Class A Convertible Preferred Units representing limited partner interests in NRP (the "Preferred Units") to certain entities controlled by funds affiliated with the Blackstone Group, L.P. (collectively referred to as "Blackstone") and certain affiliates of GoldenTree Asset Management LP (collectively referred to as "GoldenTree") (together the "Preferred Purchasers") pursuant to a Preferred Unit and Warrant Purchase Agreement. NRP issued 250,000 Preferred Units to the Preferred Purchasers at a price of $1,000 per Preferred Unit (the "Per Unit Purchase Price"), less a 2.5% structuring and origination fee. The Preferred Units entitle the Preferred Purchasers to receive cumulative distributions at a rate of 12% per year, up to one half of which NRP may pay in additional Preferred Units (such additional Preferred Units, the "PIK Units"). NRP also issued two tranches of warrants (the "Warrants") to purchase common units to the Preferred Purchasers (Warrants to purchase 1.75 million common units with a strike price of $22.81 and Warrants to purchase 2.25 million common units with a strike price of $34.00 ). The Warrants may be exercised by the holders thereof at any time before the eighth anniversary of the closing date. Upon exercise of the Warrants, NRP may, at its option, elect to settle the Warrants in common units or cash, each on a net basis. The Preferred Units have a perpetual term, unless converted or redeemed as described below. The Preferred Units (including any PIK Units) are convertible into common units at a price of $1,000 per Preferred Unit plus the value of any accrued and unpaid distributions at the election of the holders (1) after the fifth anniversary and prior to the eighth anniversary of the issue date at a 7.5% discount to the volume weighted average trading price of our common units (the "VWAP") for the 30 trading days immediately prior to the notice of conversion if the 30-day VWAP immediately prior to such notice is greater than $51.00 (subject to a maximum of 33% of the Preferred Units per year) and (2) after the eighth anniversary of the issue date at a 10% discount to the VWAP for the 30 trading days immediately prior to the notice of conversion. Instead of issuing common units pursuant to clause (1) of the preceding sentence, NRP has the option to redeem the Preferred Units proposed to be converted for cash at a price equal to the $1,000 per Preferred Unit plus the value of any accrued and unpaid distributions. To the extent the holders of the Preferred Units have not elected to convert their Preferred Units by the twelfth anniversary of the issue date, NRP has the right to force conversion of the Preferred Units at a price equal to the $1,000 per Preferred Unit plus the value of any accrued and unpaid distributions into common units at a 10% discount to the VWAP for the 30 trading days immediately prior to the notice of conversion. In addition, NRP has the ability to redeem at any time (subject to compliance with its debt agreements) all or any portion of the Preferred Units (including PIK Units) for cash at the agreed upon per unit amount, which is calculated as the Per Unit Purchase Price multiplied by (i) prior to the third anniversary of the closing date, 1.50 , (ii) on or after the third anniversary of the closing date and prior to the fourth anniversary of the closing date, 1.70 and (iii) on or after the fourth anniversary of the closing date, 1.85 ; less all Preferred Unit distributions made by NRP at the time of redemption; plus the value of all accrued and unpaid Preferred Unit distributions. The Preferred Units are redeemable at the option of the Preferred Unit Purchasers only upon a change in control. The terms of the Preferred Units contain certain restrictions on NRP's ability to pay distributions on its common units. To the extent that either (i) NRP's consolidated Leverage Ratio, as defined in the Partnership's Fifth Amended and Restated Partnership Agreement dated March 2, 2017 (the "Restated Partnership Agreement"), is greater than 3.25 x, or (ii) the ratio of NRP's Distributable Cash Flow (as defined in the Restated Partnership Agreement) to cash distributions made or proposed to be made is less than 1.2 x (in each case, with respect to the most recently completed four-quarter period), NRP may not increase the quarterly distribution above $0.45 per quarter without the approval of the holders of a majority of the outstanding Preferred Units. In addition, if at any time after January 1, 2022, any PIK Units are outstanding, NRP may not make distributions on its common units until it has redeemed all PIK Units for cash. The holders of the Preferred Units have the right to vote with holders of NRP’s common units on an as-converted basis and have other customary approval rights with respect to changes of the terms of the Preferred Units. In addition, Blackstone has certain approval rights over certain matters as identified in the Restated Partnership Agreement. GoldenTree also has more limited approval rights that will expand once Blackstone's ownership goes below the Minimum Preferred Unit Threshold (as defined below). These approval rights are not transferrable without NRP's consent. In addition, the approval rights held by Blackstone and GoldenTree will terminate at such time that Blackstone (together with their affiliates) or GoldenTree (together with their affiliates), as applicable, no longer own at least 20% of the total number of Preferred Units issued on the closing date, together with all PIK Units that have been issued but not redeemed (the "Minimum Preferred Unit Threshold"). At the closing, pursuant to a Board Representation and Observation Rights Agreement, the Preferred Purchasers received certain board appointment and observation rights, and Blackstone appointed one director and one observer to the Board of Directors of GP Natural Resource Partners LLC. NRP also entered into a registration rights agreement (the "Preferred Unit and Warrant Registration Rights Agreement") with the Preferred Purchasers, pursuant to which NRP is required to file (i) a shelf registration statement to register the common units issuable upon exercise of the Warrants and to cause such registration statement to become effective not later than 90 days following the closing date and (ii) a shelf registration statement to register the common units issuable upon conversion of the Preferred Units and to cause such registration statement to become effective not later than the earlier of the fifth anniversary of the closing date or 90 days following the first issuance of any common units upon conversion of Preferred Units (the "Registration Deadlines"). In addition, the Preferred Unit and Warrant Registration Rights Agreement gives the Preferred Purchasers piggyback registration and demand underwritten offering rights under certain circumstances. The shelf registration statement to register the common units issuable upon exercise of the Warrants became effective on April 20, 2017. If the shelf registration statement to register the common units issuable upon conversion of the Preferred Units is not effective by the applicable Registration Deadline, NRP will be required to pay the Preferred Purchasers liquidated damages in the amounts and upon the term set forth in the Preferred Unit and Warrant Registration Rights Agreement. Accounting for the Preferred Units and Warrants Classification The Preferred Units are accounted for on NRP's consolidated balance sheet as temporary equity due to certain contingent redemption rights that may be exercised at the election of Preferred Purchasers. The Warrants are accounted for on NRP's consolidated balance sheet as a liability because of a "down-round" anti-dilution price protection provision that reduces the Warrant holders' exercise price if NRP sells common units at a price less than the current strike price (subject to certain exceptions). Initial Measurement NRP allocated the transaction issuance costs to the Preferred Units and Warrants primarily on a pro-rata basis based on their relative inception date fair value. The Preferred Units and Warrants were initially recognized at fair value by allocating the transaction price as follows: March 2, 2017 Transaction price, gross $ 250,000 Structuring, origination and other fees to Preferred Purchasers (7,900 ) Transaction costs to other third parties (10,531 ) Transaction price, net $ 231,569 Allocation of net transaction price Preferred Units, net $ 159,292 Warrant liabilities 77,986 Issuance costs allocated to Warrants and expensed (5,709 ) Transaction price, net $ 231,569 Subsequent Measurement Subsequent adjustment of the Preferred Units will not occur until NRP has determined that the conversion or redemption of all or a portion of the Preferred Units is probable of occurring. Once conversion or redemption becomes probable of occurring, the carrying amount of the Preferred Units will be accreted to their redemption value over the period from the date the feature is probable of occurring to the date the preferred stock can first be converted or redeemed. The Warrants and embedded derivatives are accounted for at fair value and are remeasured each quarter. See Note 11. Fair Value Measurements for further information regarding valuation of Warrants and embedded derivatives. The financial position of the Preferred Units and Warrants as of March 31, 2017 was as follows (in thousands): March 31, 2017 Preferred Units $ 159,292 Warrant liabilities 61,417 NRP recognizes Preferred Unit distributions on the date the distribution is declared. Income available to common unitholders and the general partner is reduced by Preferred Unit distributions that accumulated during the period. During the three months ended March 31, 2017, NRP declared no distributions on the Preferred Units and $2.5 million in Preferred Unit distributions accumulated during the period. As a result, NRP reduced net income attributable to common unitholders and the general partner by $2.5 million in calculating basic earnings per common unit for the three months ended March 31, 2017.

Net Income Per Limited Unit

Net Income Per Limited Unit	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Net Income Per Limited Unit	Net Income Per Common Unit Basic net income per common unit is computed by dividing net income, after considering income attributable to preferred unitholders and the general partner’s interest, by the weighted average number of common units outstanding. Diluted net income per common unit includes the effect of NRP's Warrants and Preferred Units (see Note 2. Convertible Preferred Units and Warrants ), if the inclusion of these items is dilutive. The dilutive effect of the Warrants is calculated using the treasury stock method, which assumes that the proceeds from the exercise of these instruments are used to purchase common units at the average market price for the period. The dilutive effect of the Preferred Units is calculated using the if-converted method. Under the if-converted method, the Preferred Units are assumed to be converted at the beginning of the period, and the resulting common units are included in the denominator of the diluted EPU calculation for the period being presented. Interest recognized during the period (including the effect of accretion of discounts and amortization of issuance costs, if any) and distributions declared in the period and undeclared distributions on the Preferred Units that accumulated during the period are added back to the numerator for purposes of the if-converted calculation. The following table reconciles net income and weighted average units used in computing basic and diluted net income per common unit is as follows: Three Months Ended 2017 2016 Allocation of net income: Net income from continuing operations $ 16,971 $ 26,351 Less: net income from continuing operations attributable to the general partner 220 461 Less: income attributable to preferred unitholders 2,500 — Net income from continuing operations attributable to common unitholders $ 14,251 $ 25,890 Net loss from discontinued operations $ (207 ) $ (2,924 ) Less: net loss from discontinued operations attributable to the general partner (4 ) (58 ) Net loss from discontinued operations attributable to common unitholders $ (203 ) $ (2,866 ) Net income $ 16,764 $ 23,427 Less: net income attributable to the general partner 216 403 Less: income attributable to preferred unitholders 2,500 — Net income attributable to common unitholders $ 14,048 $ 23,024 Basic Income (Loss) per Unit: Weighted average common units—basic 12,232 12,232 Basic net income from continuing operations per common unit $ 1.17 $ 2.12 Basic net loss from discontinued operations per common unit $ (0.02 ) $ (0.23 ) Basic net income per common unit $ 1.15 $ 1.88 Diluted Income (Loss) per Unit: Weighted average common units—basic 12,232 12,232 Plus: dilutive effect of Warrants 322 — Plus: dilutive effect of Preferred Units 2,391 — Weighted average common units—diluted 14,945 12,232 Net income from continuing operations attributable to common unitholders $ 14,251 $ 25,890 Less: other income from Warrant liability fair value adjustments 16,237 — Plus: income attributable to preferred unitholders 2,500 — Diluted net income from continuing operations attributable to common unitholders $ 514 $ 25,890 Diluted net loss from discontinued operations attributable to common unitholders $ (203 ) $ (2,866 ) Net income attributable to common unitholders $ 14,048 $ 23,024 Less: other income from Warrant liability fair value adjustments 16,237 — Plus: income attributable to preferred unitholders 2,500 — Diluted net income attributable to common unitholders $ 311 $ 23,024 Diluted net income from continuing operations per common unit $ 0.03 $ 2.12 Diluted net loss from discontinued operations per common unit $ (0.01 ) $ (0.23 ) Diluted net income per common unit $ 0.02 $ 1.88

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Partnership's operating 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 three operating segments: Coal Royalty and Other —consists primarily of coal royalty and coal related transportation and processing assets. Other assets include aggregate royalty, industrial mineral royalty, oil and gas royalty and timber. The Partnership's coal reserves are primarily located in Appalachia, the Illinois Basin and the Western United States. The Partnership's aggregates and industrial minerals are located in a number of states across the United States. The Partnership's oil and gas royalty assets are located in Louisiana. 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, the Partnership's 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. The Partnership receives regular quarterly distributions from this business. VantaCore —consists of the Partnership's construction materials business 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. 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, net on the Consolidated Statements of Comprehensive Income. 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 Royalty and Other Soda Ash VantaCore Corporate and Financing Total March 31, 2017 Revenues (including affiliates) $ 51,138 $ 10,294 $ 27,221 $ — $ 88,653 Intersegment revenues (expenses) 62 — (62 ) — — Gain on asset sales 29 — 15 — 44 Operating and maintenance expenses (including affiliates) 7,384 — 24,799 — 32,183 General and administrative (including affiliates) — — — 7,202 7,202 Depreciation, depletion and amortization (including affiliates) 6,973 — 3,519 — 10,492 Asset impairment 1,778 — — — 1,778 Other expense, net — — 395 19,676 20,071 Net income (loss) from continuing operations 35,094 10,294 (1,539 ) (26,878 ) 16,971 Net loss from discontinued operations — — — — (207 ) March 31, 2016 Revenues (including affiliates) $ 39,418 $ 9,801 $ 24,682 $ — $ 73,901 Intersegment revenues (expenses) 21 — (21 ) — — Gain (loss) on asset sales 21,925 — — — 21,925 Operating and maintenance expenses 8,113 — 22,156 — 30,269 General and administrative (including affiliates) — — — 4,172 4,172 Depreciation, depletion and amortization (including affiliates) 6,940 — 3,562 — 10,502 Asset impairment 1,893 — — — 1,893 Other expense, net — — — 22,639 22,639 Net income (loss) from continuing operations 44,418 9,801 (1,057 ) (26,811 ) 26,351 Net loss from discontinued operations — — — — (2,924 ) Total assets at March 31, 2017: Continuing operations 956,782 252,803 187,239 111,434 1,508,258 Discontinued operations — — — — 991 Total assets at December 31, 2016: Continuing operations 990,172 255,901 190,615 7,002 1,443,690 Discontinued operations — — — — 991

Discontinued Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations In July 2016, NRP Oil and Gas sold its non-operated oil and gas working interest assets for $116.1 million in gross sales proceeds. The sale had an effective date of April 1, 2016. The Partnership's exit from its non-operated oil and gas working interest business represented a strategic shift to reduce debt and focus on its soda ash, coal royalty and construction aggregates business segments. As a result, the Partnership classified the operating results, cash flows and assets and liabilities of its non-operated oil and gas working interest assets as discontinued operations in its consolidated statements of comprehensive income and consolidated statements of cash flows for all periods presented. The Partnership transitioned the remaining investments in royalty interests in oil and natural gas properties into the Coal Royalty and Other operating segment during the third quarter of 2016. The following table (in thousands) presents summarized financial results of the Partnership's discontinued operations in the Consolidated Statements of Comprehensive Income: Three Months Ended 2017 2016 Revenues and other income: Oil and gas $ 15 $ 6,925 Loss on asset sales (79 ) — Total revenues and other income (64 ) 6,925 Operating expenses: Operating and maintenance expenses (including affiliates) 143 4,381 Depreciation, depletion and amortization — 4,241 Asset impairments — 137 Total operating expenses 143 8,759 Interest expense — (1,090 ) Loss from discontinued operations $ (207 ) $ (2,924 ) The following table (in thousands) presents the carrying amounts of the Partnership's assets and liabilities of discontinued operations in the Consolidated Balance Sheets: March 31, December 31, 2017 2016 ASSETS Current assets: Accounts receivable, net (including affiliates) (1) $ 991 $ 991 Total current assets 991 991 Total assets of discontinued operations $ 991 $ 991 LIABILITIES Current liabilities: Other (including affiliates) (1) $ 304 $ 353 Total current liabilities 304 353 Total liabilities of discontinued operations $ 304 $ 353 (1) See Note 12. Related Party Transactions for additional information on the Partnership's related party assets and liabilities. The following table (in thousands) presents supplemental cash flow information of the Partnership's discontinued operations: Three Months Ended 2017 2016 Cash paid for interest $ — $ 631 Plant, equipment and mineral rights funded with accounts payable or accrued liabilities — 811 Capital expenditures related to the Partnership's discontinued operations were $0.0 million and $1.9 million during the three months ended March 31, 2017 and 2016, respectively.

Equity Investment

Equity Investment	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment	Equity Investment The Partnership accounts for its 49% investment in Ciner Wyoming using the equity method of accounting. Ciner Wyoming distributed $12.3 million to the Partnership in each of the three month periods ended March 31, 2017 and 2016 . 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 $148.8 million and $150.0 million as of March 31, 2017 and December 31, 2016 , 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. The Partnership's equity in the earnings of Ciner Wyoming is summarized as follows (in thousands): Three Months Ended March 31, 2017 2016 Income allocation to NRP’s equity interests $ 11,480 $ 10,996 Amortization of basis difference (1,186 ) (1,195 ) Equity in earnings of unconsolidated investment $ 10,294 $ 9,801 The results of Ciner Wyoming’s operations are summarized as follows (in thousands): Three Months Ended 2017 2016 Sales $ 126,572 $ 114,384 Gross profit 28,697 28,251 Net Income 23,428 22,441 The financial position of Ciner Wyoming is summarized as follows (in thousands): March 31, December 31, 2017 2016 Current assets $ 142,218 $ 134,616 Non-current assets 233,209 235,427 Current liabilities 52,452 55,396 Non-current liabilities 110,655 98,425 The purchase agreement for the acquisition of the Partnership’s interest in Ciner 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 quarter of 2016, the Partnership paid $7.2 million in contingent consideration to Anadarko for performance criteria met by Ciner Wyoming in 2015. The Partnership has no further contingent consideration payments due to Anadarko.

Plant and Equipment

Plant and Equipment	3 Months Ended
	Mar. 31, 2017
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, 2017 2016 Plant and equipment at cost $ 81,199 $ 79,171 Construction in process 573 557 Less accumulated depreciation (33,193 ) (30,285 ) Total plant and equipment, net $ 48,579 $ 49,443 Depreciation expense related to the Partnership's plant and equipment totaled $3.0 million and $3.4 million for the three months ended March 31, 2017 and 2016 , respectively.

Mineral Rights

Mineral Rights	3 Months Ended
	Mar. 31, 2017
Extractive Industries [Abstract]
Mineral Rights	Mineral Rights and Land The Partnership’s mineral rights consist of the following (in thousands): March 31, 2017 Carrying Value Accumulated Depletion Net Book Value Coal properties $ 1,170,700 $ (425,378 ) $ 745,322 Aggregates properties 176,774 (40,093 ) 136,681 Oil and gas royalty properties 12,395 (6,506 ) 5,889 Other 7,179 — 7,179 Total $ 1,367,048 $ (471,977 ) $ 895,071 December 31, 2016 Carrying Value Accumulated Depletion Net Book Value Coal properties $ 1,170,904 $ (420,032 ) $ 750,872 Aggregates properties 176,774 (39,056 ) 137,718 Oil and gas royalty properties 12,395 (6,289 ) 6,106 Other 14,946 (1,450 ) 13,496 Total $ 1,375,019 $ (466,827 ) $ 908,192 Depletion expense related to the Partnership’s mineral rights totaled $6.6 million and $6.1 million for the three months ended March 31, 2017 and 2016 , respectively. In March 2017, the Partnership entered into an agreement to sell certain land and timber rights within its Coal Royalty and Other segment. As a result of the agreement, the Partnership determined it met held for sale criteria and classified $17.5 million of total net book value consisting of $13.0 million of land and $4.5 million of mineral rights in Current assets held for sale on the Partnership's Consolidated Balance Sheet as of March 31, 2017, and recorded $1.8 million of asset impairment expense during the three months ended March 31, 2017. The Partnership intends to use the proceeds to repay debt. 2016 Sale of Royalty Properties The Partnership completed the sale of the following assets during the three months ended March 31, 2016: 1) Oil and gas royalty and overriding royalty interests in the Coal Royalty and Other segment in several producing properties located in the Appalachian Basin for $37.5 million gross sales proceeds. 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, net on its Consolidated Statement of Comprehensive Income. 2) Aggregates reserves and related royalty rights in the Coal Royalty and Other segment at three aggregates operations located in Texas, Georgia and Tennessee for $10.0 million gross sales proceeds. 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, net on its Consolidated Statement of Comprehensive Income.

Intangible Assets (Including Af

Intangible Assets (Including Affiliate)	3 Months Ended
	Mar. 31, 2017
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 the Partnership receives throughput fees for the handling and transportation of coal as follows (in thousands): March 31, December 31, 2017 2016 Intangible assets—affiliate $ 81,109 $ 81,109 Less accumulated amortization—affiliate (32,066 ) (31,298 ) Total intangible assets, net—affiliate $ 49,043 $ 49,811 Amortization expense related to the Partnership's intangible assets—affiliate totaled $0.8 million and $0.7 million for the three months ended March 31, 2017 and 2016 , respectively. The Partnership's Intangible assets consist of permits, aggregates-related trade names and other agreements as follows (in thousands): March 31, December 31, 2017 2016 Intangible assets $ 5,227 $ 5,227 Less accumulated amortization (2,162 ) (1,991 ) Total intangible assets, net $ 3,065 $ 3,236 Amortization expense related to the Partnership's intangible assets totaled $0.2 million for both the three months ended March 31, 2017 and 2016 .

Debt

Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt As of March 31, 2017 and December 31, 2016 , the Partnership's debt consisted of the following (in thousands): March 31, December 31, 2017 2016 NRP LP debt: 10.500% senior notes, with semi-annual interest payments in March and September, due March 2022, $241 million issued at par and $105 million issued at 98.75% $ 345,638 $ — 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% 184,362 425,000 Opco debt: Revolving credit facility, due April 2020 — 210,000 Senior notes 4.91% with semi-annual interest payments in June and December, with annual principal payments in June, due June 2018 9,187 9,187 8.38% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2019 42,686 64,029 5.05% with semi-annual interest payments in January and July, with annual principal payments in July, due July 2020 30,633 30,633 5.55% with semi-annual interest payments in June and December, with annual principal payments in June, due June 2023 18,825 18,825 4.73% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2023 52,204 52,204 5.82% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 104,583 119,524 8.92% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 31,738 36,272 5.03% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 134,035 134,035 5.18% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 38,262 38,262 5.31% utility local improvement obligation, with annual principal and interest payments in February, due March 2021 769 961 Total debt at face value $ 992,922 $ 1,138,932 Net unamortized debt discount (2,184 ) (1,322 ) Net unamortized debt issuance costs (19,812 ) (11,307 ) Total debt, net $ 970,926 $ 1,126,303 Less: current portion of long-term debt 263,502 138,903 Total long-term debt $ 707,424 $ 987,400 NRP LP Debt 2018 Senior Notes In September 2013, the Partnership, together with NRP Finance Corporation ("NRP Finance"), a wholly owned subsidiary of the Partnership, as co-issuer, issued $300.0 million of 9.125% Senior Notes at an offering price of 99.007% of par (the "2018 Senior Notes"). Net proceeds after expenses from the issuance of 2018 Senior Notes were approximately $289.0 million . Interest on the 2018 Senior Notes is paid semi-annually on April 1 and October 1, and the 2018 Senior Notes will mature on October 1, 2018. None of the Partnership's subsidiaries guarantee the 2018 Senior Notes. In October 2014, the Partnership, together with NRP Finance as co-issuer, issued an additional $125.0 million of the 2018 Senior Notes at an offering price of 99.5% of par. The additional issuance constituted the same series of securities as the existing 2018 Senior Notes. The Partnership and NRP Finance have the option to redeem the 2018 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 2018 Senior Notes (the "2018 Indenture"). The 2018 Indenture contains covenants that, among other things, limit the ability of the Partnership and certain of its subsidiaries to incur or guarantee additional indebtedness. Under the 2018 Indenture, the Partnership 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 the Partnership and certain of its subsidiaries to incur additional indebtedness is further limited in the event the amount of indebtedness of the Partnership and certain of its subsidiaries that is senior to the Partnership's unsecured indebtedness exceeds certain thresholds. In March 2017, the Partnership and NRP Finance exchanged $241 million aggregate principal amount of the 2018 Senior Notes for $241 million aggregate principal amount of a new series of 10.500% Senior Notes due 2022 (the “2022 Senior Notes”). In April 2017, the Partnership and NRP Finance redeemed $90 million in aggregate principal amount of the 2018 Senior Notes at a redemption price of 104.563% , and paid all accrued and unpaid interest thereon. In addition, pursuant to the 2022 Indenture (as defined below), the Partnership and NRP Finance will redeem any and all remaining outstanding 2018 Senior Notes at par (and pay accrued and unpaid interest thereon) within 60 days after October 1, 2017. NRP anticipates using cash on hand and available borrowings under the Opco Credit Facility in order pay the October 2017 redemption of the 2018 Senior Notes. 2022 Senior Notes In March 2017, NRP and NRP Finance issued $346 million aggregate principal amount of 2022 Senior Notes to several holders of their 2018 Senior Notes. Of the $346 million of 2022 Senior Notes issued, $241 million in aggregate principal amount were issued in exchange for $241 million in aggregate principal amount of 2018 Senior Notes, and $105 million of the 2022 Senior Notes were issued to the holders for cash. The 2022 Senior Notes are issued under an Indenture dated as of March 2, 2017 (the "2022 Indenture"), bear interest at 10.500% per year, are payable semi-annually on March 15 and September 15, beginning September 15, 2017, and mature on March 15, 2022. The $105.0 million in 2022 Senior Notes purchased for cash were issued at a price of 98.75% (original issue discount of 1.25% ), and each holder exchanging 2018 Senior Notes received a fee of 5.813% of the aggregate principal amount of all 2018 Senior Notes tendered for exchange by such holder, as well as all accrued and unpaid interest thereon. The 5.813% fee included a 4.563% call premium on the early repayment of the 2018 Senior Notes and a 1.25% fee on the exchange of the 2018 Notes for 2022 Senior Notes. This fee is accounted for as a debt issue cost, capitalized and shown net of the debt liability on our consolidated balance sheets. NRP and NRP Finance have the option to redeem the 2022 Senior Notes, in whole or in part, at any time on or after March 15, 2019, at the redemption prices (expressed as percentages of principal amount) of 105.25% for the 12-month period beginning March 15, 2019, 102.625% for the 12-month period beginning March 15, 2020, and thereafter at 100.000% , together, in each case, with any accrued and unpaid interest to the date of redemption. Furthermore, before March 15, 2019, NRP may on any one or more occasions redeem up to 35% of the aggregate principal amount of the 2022 Senior Notes with the net proceeds of certain public or private equity offerings at a redemption price of 110.500% of the principal amount of 2022 Senior Notes, plus any accrued and unpaid interest, if any, to the date of redemption, if at least 65% of the aggregate principal amount of the 2022 Senior Notes issued under the 2022 Indenture remains outstanding immediately after such redemption and the redemption occurs within 180 days of the closing date of such equity offering. In the event of a change of control, as defined in the 2022 Indenture, the holders of the 2022 Senior Notes may require us to purchase their 2022 Senior Notes at a purchase price equal to 101% of the principal amount of the 2022 Senior Notes, plus accrued and unpaid interest, if any. The 2022 Indenture contains restrictive covenants that are substantially similar to those contained in the Indenture governing the 2018 Senior Notes, except that the debt incurrence and restricted payments covenants contain additional restrictions. Under the debt incurrence covenant, NRP's non-guarantor restricted subsidiaries will not be permitted to incur additional indebtedness unless their consolidated leverage ratio is less than 3.00 x (measured on a pro forma basis and assuming that the greater of (i) $150.0 million of debt (or, if less, at NRP's election, the amount of total lending commitments under any revolving credit facility) and (ii) the actual amount of debt outstanding is outstanding under any revolving credit facility); provided, however, that such non-guarantor restricted subsidiaries will be permitted to make up to $150 million in borrowings under a revolving credit facility (which amount will be reduced on a dollar-for-dollar basis to the extent we have made the election described in clause (i) above). Under the restricted payments covenant, NRP will not be able to increase the quarterly distribution on its common units or elect to pay more than 50% of the distributions required to be made on the Preferred Units in cash, unless, in each case, its consolidated leverage ratio is less than 4.00 x. The 2022 Indenture also contains restrictions on NRP's ability to redeem the Preferred Units. The 2022 Senior Notes are the senior unsecured obligations of NRP and NRP Finance. The 2022 Senior Notes rank equal in right of payment to all existing and future senior unsecured debt of NRP and NRP Finance, including the remaining outstanding 2018 Senior Notes, and senior in right of payment to any of NRP's subordinated debt. The 2022 Senior Notes are effectively subordinated in right of payment to all future secured debt of NRP and NRP Finance to the extent of the value of the collateral securing such indebtedness and are structurally subordinated in right of payment to all existing and future debt and other liabilities of our subsidiaries, including the Opco Credit Facility and each series of Opco’s existing senior notes. None of NRP's subsidiaries guarantee the 2022 Senior Notes. 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, 2017 and December 31, 2016, Opco was in compliance with the terms of the financial covenants contained in its debt agreements. Opco Credit Facility Opco’s $180 million Third Amended and Restated Credit Agreement, as amended through March 2017 (the "Opco Credit Facility"), matures on April 30, 2020, 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. Commitments under the Opco Credit Facility will be reduced to $150 million at December 31, 2017 and further reduced to $100 million at December 31, 2018 through maturity in April 2020. Indebtedness under the Opco Credit Facility bears interest, at Opco'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 1% , in each case plus an applicable margin ranging from 2.50% to 3.50% ; or • a rate equal to LIBOR plus an applicable margin ranging from 3.50% to 4.50% . The weighted average interest rates for the borrowings outstanding under the Opco Credit Facility for three months ended March 31, 2017 and 2016 were 5.22% and 3.80% , 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 Opco Credit Facility at any time without penalty. As of March 31, 2017, Opco had no indebtedness outstanding under the Opco Credit Facility. The Opco Credit Facility contains financial covenants requiring Opco to maintain: • a leverage ratio of consolidated indebtedness to EBITDDA (as defined in the Opco Credit Facility) not to exceed 4.0 x; provided, however, that if NRP increases its quarterly distribution to its common unitholders above $0.45 per common unit, the maximum leverage ratio under the Opco Credit Facility will permanently decrease from 4.0 x to 3.0 x. • a fixed charge coverage 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. The Opco 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. In addition, Opco is required to use 75% of the net cash proceeds of certain non-ordinary course asset sales to repay the Opco Credit Facility (without any corresponding commitment reduction) and use the remaining 25% of the net cash proceeds to offer to repay its senior notes on a pro rata basis, as described below under “—Opco Senior Notes.” The Opco Credit Facility also contains customary events of default, including cross-defaults under Opco’s senior notes. The Opco Credit Facility is collateralized and secured by liens on certain of Opco’s assets with carrying values of $660.7 million and $673.0 million classified as Land, Plant and equipment and Mineral rights on the Partnership’s Consolidated Balance Sheet as of March 31, 2017 and December 31, 2016, 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 business, 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, 2017 and December 31, 2016, the Opco Senior Notes had cumulative principal balances of $462.2 million and $503.0 million , respectively. The Opco Senior Notes are guaranteed by all of Opco's wholly owned subsidiaries and are secured by the same collateral as the A&R Credit Facility. Opco made mandatory principal payments of $40.8 million and $41.0 million during the three months ended March 31, 2017 and 2016, respectively. 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. In addition, the Note Purchase Agreements include a covenant that provides that, in the event NRP Operating or any of its subsidiaries is subject to any additional or more restrictive covenants under the agreements governing its material indebtedness (including the Opco Credit Facility and all renewals, amendments or restatements thereof), such covenants shall be deemed to be incorporated by reference in the Note Purchase Agreements and the holders of the Notes shall receive the benefit of such additional or more restrictive covenants to the same extent as the lenders under such material indebtedness agreement. 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, 2017. In September 2016, Opco amended the Opco Senior Notes. Under this amendment, Opco agreed to use certain asset sale proceeds to make mandatory prepayment offers on the Opco Senior Notes as follows: • until the earlier of the time that (1) Opco has sold $300 million of assets and (2) June 30, 2020, Opco will be required to make prepayment offers to the holders of the Opco Senior Notes using 25% of the net cash proceeds from certain asset sales; and • after the earlier to occur of the dates above, Opco will be required to make prepayment offers to the holders of the Opco Senior Notes using an amount of net cash proceeds from certain asset sales that will be calculated pro-rata based on the amount of Opco Senior Notes then outstanding compared to the other total Opco senior debt outstanding that is being prepaid. The mandatory prepayment offers described above will be made pro-rata across each series of outstanding Opco Senior Notes and will not require any make-whole payment by Opco. In addition, the remaining principal and interest payments on the Opco Senior Notes will be adjusted accordingly based on the amount of Opco Senior Notes actually prepaid. The prepayments do not affect the maturity dates of any series of the Opco Senior Notes.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
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, Warrants, debt and convertible preferred units. The carrying amounts reported on the Consolidated Balance Sheets for cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their short-term nature. Fair Value—Disclosure Only The following table (in thousands) shows the carrying amount and estimated fair value of the Partnership's debt and contracts receivable—affiliate: March 31, 2017 December 31, 2016 Carrying Value Estimated Carrying Estimated Debt: NRP 2018 Senior Notes (1) $ 183,518 $ 187,358 $ 420,097 $ 412,250 NRP 2022 Senior Notes (1) 336,669 357,735 — — Opco Senior Notes and utility local improvement obligation (2) 459,288 479,124 500,174 488,814 Opco Revolving Credit Facility (3) — — 206,032 210,000 Assets: Contracts receivable—affiliate, current and long-term(2) 46,118 32,049 46,742 32,554 (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 outstanding borrowing 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. Fair Value—Recurring Warrants entered into in March 2017 are reported on the Partnership's consolidated balance sheets as a liability at Level 3 fair value using a binomial lattice model under the option pricing method. This model incorporates transaction details such as contractual terms, the Partnership’s common unit price, risk free interest rate, dividend yield and volatility. A significant decrease in the volatility or a significant decrease in the Partnership’s unit price, in isolation, would result in a significantly lower fair value measurement, and vice versa. The Warrants' binomial lattice model utilized the following assumptions on the following dates (fair value in thousands): Warrant Valuation Model Key Assumptions March 2, 2017 March 31, 2017 Closing price of NRP common units $ 41.95 $ 36.15 Risk-free interest rate 2.38 % 2.28 % Expected dividend yield 4.29 % 4.98 % Expected volatility 45.00 % 47.50 % The Warrants are recorded as non-current liabilities on the Partnership's consolidated balance sheets. Changes in the estimated fair value of the Warrants result in the recognition of other income or expense. The following table (in thousands) sets forth a summary of the beginning and ending balance sheet amounts and the changes in fair value of the Partnership's Level 3 Warrant liabilities that are measured at fair value on a recurring basis: Three Months Ended March 31, 2017 2016 Beginning balance $ — $ — Issuance of new Warrants 77,986 — Fair value adjustments for Warrant liabilities (16,569 ) — Ending balance (1) $ 61,417 $ — (1) During the three months ended March 31, 2017, there were no transfers in or out of Level 3 from other levels in the fair value hierarchy. NRP has embedded derivatives in the Preferred Units related to certain conversion options, redemption features and the change of control provision that are accounted for separately from the Preferred Units as assets and liabilities at fair value in NRP's consolidated balance sheets. Level 3 valuation of the embedded derivatives are based on numerous factors including the likelihood of the event occurring. The embedded derivatives are revalued quarterly, and changes in their fair value would be recorded in other income (expense) in NRP's consolidated statements of comprehensive income. The embedded derivatives had zero value at inception and as of March 31, 2017.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2017
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 Partnership'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 and were $0.1 million during both the three months ended March 31, 2017 and 2016 . 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 rent, legal, accounting, treasury, information technology, insurance, administration of employee benefits and other corporate services incurred by or on behalf of 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 QMC of $0.7 million and $0.4 million , including $0.0 million and less than $0.1 million related to discontinued operations at March 31, 2017 and December 31, 2016 , respectively, for services provided by QMC to the Partnership. The Partnership had Accounts payable—affiliates to WPPLP of $0.5 million and $0.6 million at March 31, 2017 and December 31, 2016 , respectively. Direct general and administrative expenses charged to the Partnership by WPPLP and QMC are as follows (in thousands): Three Months Ended March 31, 2017 2016 Operating and maintenance expenses—affiliates, net 2,135 2,776 General and administrative—affiliates 1,124 937 Included in income (loss) from discontinued operations are $0.0 million and $0.3 million of operating and maintenance expenses charged by QMC for the three months ended March 31, 2017 and 2016, respectively. Cline Affiliates Various companies affiliated with Chris Cline, including Foresight Energy LP, 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 ("Adena"), owns a 31% interest (unaudited) in NRP's general partner, as well as approximately 0.5 million of NRP's common units (unaudited) at March 31, 2017. Coal related revenues from Foresight Energy totaled $15.8 million and $10.1 million for the three months ended March 31, 2017 and 2016 , respectively. As of March 31, 2017 and December 31, 2016 , the Partnership had Accounts receivable—affiliates from Foresight Energy of $7.5 million and $6.5 million , respectively. As of March 31, 2017 and December 31, 2016, the Partnership had received $68.7 million and $71.6 million , respectively in minimum royalty payments to date that have been recorded as Deferred revenue—affiliates since they have not been recouped by Foresight Energy. NRP 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, 2017 were $75.2 million with unearned income of $30.9 million , and the net amount receivable was $44.2 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, 2016 were $76.4 million with unearned income of $31.8 million and the net amount receivable was $44.6 million , of which $2.2 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliates on the accompanying Consolidated Balance Sheets. NRP 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, 2017 was $2.7 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, 2016 was $2.7 million , of which $1.4 million is included in Accounts receivable—affiliates while the remaining is included in Long-term contracts receivable—affiliate on the accompanying Consolidated Balance Sheets. NRP owns rail load out transportation assets and subcontracts out the operating responsibilities to an affiliate of Foresight Energy at Foresight's Williamson mine. During the three months ended March 31, 2017 and 2016, the Partnership recorded operating and maintenance expenses—affiliates of $0.3 million and $0.4 million , respectively, to operate these assets. 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, 2017 , 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 $0.4 million and $0.5 million for the three months ended March 31, 2017 and 2016 , respectively. As of March 31, 2017 and December 31, 2016 the Partnership had Accounts receivable—affiliates totaling $0.1 million and $0.2 million from Corsa at March 31, 2017 and December 31, 2016, respectively. WPPLP Production Royalty and Overriding Royalty During the three months ended March 31, 2017 and 2016, the Partnership recorded $0.1 million and $0.6 million , respectively 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. The Partnership had Other assets—affiliate from WPPLP of $1.0 million at both March 31, 2017 and December 31, 2016 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, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal NRP 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. The Partnership does not believe this matter will have a material effect on its financial condition or results of operations. Foresight Energy Disputes In November 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. We believe the force majeure claim by Hillsboro has no merit, and we are vigorously pursuing recovery against them. 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 three quarters of 2015, each quarter of 2016, and the first quarter of 2017 resulted in a cumulative $53.5 million negative 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. In April 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 has resulted in a cumulative $8.0 million negative cash impact to us. While the Partnership plans to pursue its claim, a valuation allowance for the receivable amount has been recorded.

Major Customers

Major Customers	3 Months Ended
	Mar. 31, 2017
Risks and Uncertainties [Abstract]
Major Customers	Major Customers Revenues from customers that exceeded ten percent of total revenues and other income for any of the periods presented below are as follows (in thousands except for percentages): Three Months Ended March 31, 2017 2016 Revenues Percent Revenues Percent Foresight Energy (1) $ 15,791 17.8 % $ 10,078 10.5 % (1) Revenues from Foresight Energy are included within the Partnership's Coal Royalty and Other segment.

Unit-Based Compensation

Unit-Based Compensation	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	Unit-Based Compensation GP Natural Resource Partners LLC adopted the Natural Resource Partners Long-Term Incentive Plan in 2008 (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 committee of GP Natural Resource Partners LLC’s board of directors administers the Long-Term Incentive Plan. Subject to the rules of the exchange upon which the common units are listed at the time, the board of directors and the 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 the Parent 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 2017 is as follows (in thousands): Phantom Units Outstanding grants at January 1, 2017 86 Grants vested and paid during the period (26 ) Forfeitures during the period (4 ) Outstanding grants at March 31, 2017 56 Grants typically vest at the end of a four -year period and are paid in cash upon vesting. During the three months ended March 31, 2017, the Partnership recorded G&A expenses of $0.4 million . The Partnership recorded a credit to general and administrative expenses related to its Long-Term Incentive Plan of less than $0.1 million for the three months ended March 31, 2016, 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 $1.7 million and $1.5 million were made during the three months ended March 31, 2017 and 2016, respectively. The unaccrued cost associated with unvested outstanding grants and related DERs at March 31, 2017 and December 31, 2016 was $0.7 million and $0.8 million , respectively.

Cash Distributions

Cash Distributions	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Cash Distributions	Cash Distributions The following table shows the distributions paid by the Partnership during the three months ended March 31, 2017 and 2016: Total Distributions (In thousands) Date Paid Period Covered by Distribution Distribution per Common Unit Common Units GP Interest Total 2017 February 14, 2017 October 1 - December 31, 2016 $ 0.45 $ 5,503 $ 112 $ 5,615 2016 February 12, 2016 October 1 - December 31, 2015 $ 0.45 $ 5,503 $ 113 $ 5,616

Deferred Revenue and Deferred R

Deferred Revenue and Deferred Revenue - Affiliate	3 Months Ended
	Mar. 31, 2017
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 pay the Partnership minimum annual or quarterly amounts which are generally recoupable out of actual production over certain time periods. These minimum payments are recorded as a deferred revenue liability 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, 2017 December 31, 2016 Deferred revenue $ 46,008 $ 44,931 Deferred revenue—affiliate 68,735 71,632 Total deferred revenue (including affiliate) $ 114,743 $ 116,563 The Partnership recognized the following amounts of deferred revenue (including affiliate) attributable to previously paid minimums resulting from the expiration of the lessee’s ability to recoup the payments as Coal royalty and other revenue (in thousands): Three Months Ended March 31, 2017 2016 Coal royalty and other $ 758 $ 6,094 Coal royalty and other—affiliates 4,438 870 Total coal royalty and other (including affiliates) $ 5,196 $ 6,964

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The following represents material events that have occurred subsequent to March 31, 2017 through the time of the Partnership’s filing of its Quarterly Report on Form 10-Q with the SEC: Distributions Declared On April 25, 2017, 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 12, 2017 to common unitholders of record on May 5, 2017. In addition, the Board declared a distribution on NRP's 12.0% Class A Convertible Preferred Units with respect to the period such units were outstanding during the first quarter. One-half of the distribution on the preferred units will be paid-in-kind through the issuance of 1,250 additional Preferred Units. Partial Redemption of 2018 Senior Notes On April 3, 2017, NRP redeemed $90 million in aggregate principal amount of its 2018 Senior Notes at a redemption price of 104.563% , and paid all accrued and unpaid interest thereon. Registration Statements and Exchange Offer In April 2017, as required by the terms of the registration rights agreements entered into in connection with the recapitalization transactions completed in March 2017, we filed (i) a Registration Statement on Form S-3 to register common units issuable upon exercise of the Warrants, and (ii) a Registration Statement on Form S-4 to register the exchange of the $346 million of 2022 Senior Notes issued in a private offering in March 2017 for $346 million of 2022 Senior Notes that have been registered under the Securities Act of 1933, as amended. Both registration statements were declared effective on April 20, 2017. The exchange offer for the 2022 Senior Notes was launched on April 20, 2017 and expires on May 23, 2017, unless we determine to extend it. Purchase of Adena Interest in NRP GP On May 9, 2017, Adena sold its 31% limited partner interest in NRP (GP) LP (the Partnership’s general partner) (“NRP GP”) to Great Northern Properties Limited Partnership (“GNPLP”) and WPPLP (the “Adena Sale”). GNPLP and WPPLP are companies controlled by Corbin J. Robertson, the Chairman and Chief Executive Officer of GP Natural Resource Partners LLC (the general partner of NRP GP) (“GP LLC”). Following the Adena Sale, GNPLP owns a 9.830% limited partner interest in NRP GP, and WPPLP owns a 90.169% limited partner interest in NRP GP. GP LLC continues to own a 0.001% general partner interest in NRP GP. In connection with the Adena Sale, on May 9, 2017, the Investor Rights Agreement effective as of January 4, 2007 by and among Adena, NRP GP, GP LLC, and Robertson Coal Management (“Investor Rights Agreement”) terminated pursuant to its terms. Pursuant to the Investor Rights Agreement, Adena had the right to appoint two directors (one of whom must have been independent) and one observer to the Board of Directors of GP LLC (the “GP LLC Board”). Also on May 9, 2017, the Restricted Business Contribution Agreement effective as of January 4, 2007, by and among Christopher Cline, Foresight Reserves LP, Adena, NRP, NRP GP, and NRP (Operating) LLC (the “RBCA”) also terminated pursuant to the terms thereof. Pursuant to the RBCA, Adena and its affiliates were required to make offers of certain assets to NRP and its subsidiaries. In addition, the rights of Adena and its affiliates under the Partnership’s partnership agreement are no longer in effect as a result of the Adena Sale (other than customary rights to indemnification). In connection with the termination of the Investor Rights Agreement, Adena no longer has rights to appoint directors to the GP LLC Board, and accordingly, on May 9, 2017, L.G. (“Trey”) Jackson resigned from the GP LLC Board. Mr. Jackson was one of two Adena designees to the GP LLC Board pursuant to the Investor Rights Agreement. Upon closing of this transaction, NRP no longer considers the various companies affiliated with Chris Cline, including Foresight Energy LP (see Cline Affiliates section of Note. 12 Related Party Transactions for further information), to be affiliates of NRP.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	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. In management's opinion, all necessary adjustments to fairly present the Partnership's results of operations, financial position and cash flows for the periods presented have been made and all such adjustments were of a normal and recurring nature. Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. As described in Note 5. Discontinued Operations , the Partnership has classified the assets and liabilities, operating results and cash flows of its non-operated oil and gas working interest assets as discontinued operations in its consolidated financial statements for all periods presented. As described in Note 4. Segment Information , the Partnership has reclassified oil and gas royalty activities in prior period amounts to conform to the way it internally manages and monitors segment performance that had no impact on the Partnership's consolidated financial position, net income or cash flows. In the second quarter of 2016, the Partnership determined its net cash provided by operating and investing activities were understated by $7.2 million and $0.8 million , respectively, and net cash used in financing activities was understated by $8.0 million for the three months ended March 31, 2016. The Consolidated Statement of Cash Flows for the three months ended March 31, 2016 has been corrected for this error.
Recently Issued Accounting Standards	Recently Issued Accounting Standards The FASB issued authoritative guidance on revenue recognition. The core principle of this guidance 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. The guidance will also require enhanced disclosures, provide more comprehensive guidance for transactions such as service revenue and contract modifications, and enhance guidance for multiple-element arrangements. The Partnership is required to adopt this guidance in the first quarter of 2018 using one of two retrospective application methods. The Partnership has performed revenue scoping procedures to identify the contracts for all of its revenue streams and utilized the practical expedient of grouping contracts or performance obligations with similar characteristics as prescribed by the new standard. The Partnership is currently evaluating these contracts; and while the effect of adoption is unknown, it is not currently aware of any material changes that would result from adoption of this new revenue recognition guidance and expects to complete its assessment of how it will be affected in the second quarter of 2017. The Partnership anticipates utilizing the full retrospective adoption method for financial statement comparability and electing the practical expedient of not restating contracts that begin and are completed within the same annual reporting period. The FASB issued authoritative lease guidance that requires lessees to recognize assets and liabilities on the balance sheet for the present value of the rights and obligations created by all leases with terms of more than 12 months. The guidance also requires disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual and interim periods ending after December 31, 2018. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements. The FASB issued authoritative guidance that replaces the incurred loss impairment methodology in the current standard with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The guidance is effective for annual and interim periods ending after December 31, 2019. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements. The FASB issued authoritative guidance to clarify how certain cash receipts and cash payments are presented and classified in the statement of cash flows in order to reduce current and potential future diversity in practice. The guidance is effective for annual and interim periods ending after December 31, 2017. The Partnership is currently evaluating the impact of the provisions of this guidance on its consolidated financial statements.

Convertible Preferred Units a26

Convertible Preferred Units and Warrants Convertible Preferred Units and Warrants (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Preferred Units and Warrants Issued	The Preferred Units and Warrants were initially recognized at fair value by allocating the transaction price as follows: March 2, 2017 Transaction price, gross $ 250,000 Structuring, origination and other fees to Preferred Purchasers (7,900 ) Transaction costs to other third parties (10,531 ) Transaction price, net $ 231,569 Allocation of net transaction price Preferred Units, net $ 159,292 Warrant liabilities 77,986 Issuance costs allocated to Warrants and expensed (5,709 ) Transaction price, net $ 231,569 The financial position of the Preferred Units and Warrants as of March 31, 2017 was as follows (in thousands): March 31, 2017 Preferred Units $ 159,292 Warrant liabilities 61,417

Net Income Per Limited Unit Net

Net Income Per Limited Unit Net Income Per Limited Unit (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Reconciliation of Net Income to Weighted Average Units Outstanding	The following table reconciles net income and weighted average units used in computing basic and diluted net income per common unit is as follows: Three Months Ended 2017 2016 Allocation of net income: Net income from continuing operations $ 16,971 $ 26,351 Less: net income from continuing operations attributable to the general partner 220 461 Less: income attributable to preferred unitholders 2,500 — Net income from continuing operations attributable to common unitholders $ 14,251 $ 25,890 Net loss from discontinued operations $ (207 ) $ (2,924 ) Less: net loss from discontinued operations attributable to the general partner (4 ) (58 ) Net loss from discontinued operations attributable to common unitholders $ (203 ) $ (2,866 ) Net income $ 16,764 $ 23,427 Less: net income attributable to the general partner 216 403 Less: income attributable to preferred unitholders 2,500 — Net income attributable to common unitholders $ 14,048 $ 23,024 Basic Income (Loss) per Unit: Weighted average common units—basic 12,232 12,232 Basic net income from continuing operations per common unit $ 1.17 $ 2.12 Basic net loss from discontinued operations per common unit $ (0.02 ) $ (0.23 ) Basic net income per common unit $ 1.15 $ 1.88 Diluted Income (Loss) per Unit: Weighted average common units—basic 12,232 12,232 Plus: dilutive effect of Warrants 322 — Plus: dilutive effect of Preferred Units 2,391 — Weighted average common units—diluted 14,945 12,232 Net income from continuing operations attributable to common unitholders $ 14,251 $ 25,890 Less: other income from Warrant liability fair value adjustments 16,237 — Plus: income attributable to preferred unitholders 2,500 — Diluted net income from continuing operations attributable to common unitholders $ 514 $ 25,890 Diluted net loss from discontinued operations attributable to common unitholders $ (203 ) $ (2,866 ) Net income attributable to common unitholders $ 14,048 $ 23,024 Less: other income from Warrant liability fair value adjustments 16,237 — Plus: income attributable to preferred unitholders 2,500 — Diluted net income attributable to common unitholders $ 311 $ 23,024 Diluted net income from continuing operations per common unit $ 0.03 $ 2.12 Diluted net loss from discontinued operations per common unit $ (0.01 ) $ (0.23 ) Diluted net income per common unit $ 0.02 $ 1.88

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
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 Royalty and Other Soda Ash VantaCore Corporate and Financing Total March 31, 2017 Revenues (including affiliates) $ 51,138 $ 10,294 $ 27,221 $ — $ 88,653 Intersegment revenues (expenses) 62 — (62 ) — — Gain on asset sales 29 — 15 — 44 Operating and maintenance expenses (including affiliates) 7,384 — 24,799 — 32,183 General and administrative (including affiliates) — — — 7,202 7,202 Depreciation, depletion and amortization (including affiliates) 6,973 — 3,519 — 10,492 Asset impairment 1,778 — — — 1,778 Other expense, net — — 395 19,676 20,071 Net income (loss) from continuing operations 35,094 10,294 (1,539 ) (26,878 ) 16,971 Net loss from discontinued operations — — — — (207 ) March 31, 2016 Revenues (including affiliates) $ 39,418 $ 9,801 $ 24,682 $ — $ 73,901 Intersegment revenues (expenses) 21 — (21 ) — — Gain (loss) on asset sales 21,925 — — — 21,925 Operating and maintenance expenses 8,113 — 22,156 — 30,269 General and administrative (including affiliates) — — — 4,172 4,172 Depreciation, depletion and amortization (including affiliates) 6,940 — 3,562 — 10,502 Asset impairment 1,893 — — — 1,893 Other expense, net — — — 22,639 22,639 Net income (loss) from continuing operations 44,418 9,801 (1,057 ) (26,811 ) 26,351 Net loss from discontinued operations — — — — (2,924 ) Total assets at March 31, 2017: Continuing operations 956,782 252,803 187,239 111,434 1,508,258 Discontinued operations — — — — 991 Total assets at December 31, 2016: Continuing operations 990,172 255,901 190,615 7,002 1,443,690 Discontinued operations — — — — 991

Discontinued Operations (Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Summary of Financial Results of Discontinued Operations	The following table (in thousands) presents summarized financial results of the Partnership's discontinued operations in the Consolidated Statements of Comprehensive Income: Three Months Ended 2017 2016 Revenues and other income: Oil and gas $ 15 $ 6,925 Loss on asset sales (79 ) — Total revenues and other income (64 ) 6,925 Operating expenses: Operating and maintenance expenses (including affiliates) 143 4,381 Depreciation, depletion and amortization — 4,241 Asset impairments — 137 Total operating expenses 143 8,759 Interest expense — (1,090 ) Loss from discontinued operations $ (207 ) $ (2,924 ) The following table (in thousands) presents supplemental cash flow information of the Partnership's discontinued operations: Three Months Ended 2017 2016 Cash paid for interest $ — $ 631 Plant, equipment and mineral rights funded with accounts payable or accrued liabilities — 811 The following table (in thousands) presents the carrying amounts of the Partnership's assets and liabilities of discontinued operations in the Consolidated Balance Sheets: March 31, December 31, 2017 2016 ASSETS Current assets: Accounts receivable, net (including affiliates) (1) $ 991 $ 991 Total current assets 991 991 Total assets of discontinued operations $ 991 $ 991 LIABILITIES Current liabilities: Other (including affiliates) (1) $ 304 $ 353 Total current liabilities 304 353 Total liabilities of discontinued operations $ 304 $ 353 (1) See Note 12. Related Party Transactions for additional information on the Partnership's related party assets and liabilities.

Equity Investment (Tables)

Equity Investment (Tables)	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Summarized Financial Information	equity in the earnings of Ciner Wyoming is summarized as follows (in thousands): Three Months Ended March 31, 2017 2016 Income allocation to NRP’s equity interests $ 11,480 $ 10,996 Amortization of basis difference (1,186 ) (1,195 ) Equity in earnings of unconsolidated investment $ 10,294 $ 9,801 The results of Ciner Wyoming’s operations are summarized as follows (in thousands): Three Months Ended 2017 2016 Sales $ 126,572 $ 114,384 Gross profit 28,697 28,251 Net Income 23,428 22,441 The financial position of Ciner Wyoming is summarized as follows (in thousands): March 31, December 31, 2017 2016 Current assets $ 142,218 $ 134,616 Non-current assets 233,209 235,427 Current liabilities 52,452 55,396 Non-current liabilities 110,655 98,425

Plant and Equipment (Tables)

Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Plant and Equipment	The Partnership’s plant and equipment consist of the following (in thousands): March 31, December 31, 2017 2016 Plant and equipment at cost $ 81,199 $ 79,171 Construction in process 573 557 Less accumulated depreciation (33,193 ) (30,285 ) Total plant and equipment, net $ 48,579 $ 49,443

Mineral Rights (Tables)

Mineral Rights (Tables)	3 Months Ended
	Mar. 31, 2017
Extractive Industries [Abstract]
Mineral Rights	The Partnership’s mineral rights consist of the following (in thousands): March 31, 2017 Carrying Value Accumulated Depletion Net Book Value Coal properties $ 1,170,700 $ (425,378 ) $ 745,322 Aggregates properties 176,774 (40,093 ) 136,681 Oil and gas royalty properties 12,395 (6,506 ) 5,889 Other 7,179 — 7,179 Total $ 1,367,048 $ (471,977 ) $ 895,071 December 31, 2016 Carrying Value Accumulated Depletion Net Book Value Coal properties $ 1,170,904 $ (420,032 ) $ 750,872 Aggregates properties 176,774 (39,056 ) 137,718 Oil and gas royalty properties 12,395 (6,289 ) 6,106 Other 14,946 (1,450 ) 13,496 Total $ 1,375,019 $ (466,827 ) $ 908,192

Intangible Assets (Including 33

Intangible Assets (Including Affiliate) (Tables)	3 Months Ended
	Mar. 31, 2017
Related Party Transaction [Line Items]
Intangible Assets	The Partnership's Intangible assets consist of permits, aggregates-related trade names and other agreements as follows (in thousands): March 31, December 31, 2017 2016 Intangible assets $ 5,227 $ 5,227 Less accumulated amortization (2,162 ) (1,991 ) Total intangible assets, net $ 3,065 $ 3,236
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 the Partnership receives throughput fees for the handling and transportation of coal as follows (in thousands): March 31, December 31, 2017 2016 Intangible assets—affiliate $ 81,109 $ 81,109 Less accumulated amortization—affiliate (32,066 ) (31,298 ) Total intangible assets, net—affiliate $ 49,043 $ 49,811

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	As of March 31, 2017 and December 31, 2016 , the Partnership's debt consisted of the following (in thousands): March 31, December 31, 2017 2016 NRP LP debt: 10.500% senior notes, with semi-annual interest payments in March and September, due March 2022, $241 million issued at par and $105 million issued at 98.75% $ 345,638 $ — 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% 184,362 425,000 Opco debt: Revolving credit facility, due April 2020 — 210,000 Senior notes 4.91% with semi-annual interest payments in June and December, with annual principal payments in June, due June 2018 9,187 9,187 8.38% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2019 42,686 64,029 5.05% with semi-annual interest payments in January and July, with annual principal payments in July, due July 2020 30,633 30,633 5.55% with semi-annual interest payments in June and December, with annual principal payments in June, due June 2023 18,825 18,825 4.73% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2023 52,204 52,204 5.82% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 104,583 119,524 8.92% with semi-annual interest payments in March and September, with annual principal payments in March, due March 2024 31,738 36,272 5.03% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 134,035 134,035 5.18% with semi-annual interest payments in June and December, with annual principal payments in December, due December 2026 38,262 38,262 5.31% utility local improvement obligation, with annual principal and interest payments in February, due March 2021 769 961 Total debt at face value $ 992,922 $ 1,138,932 Net unamortized debt discount (2,184 ) (1,322 ) Net unamortized debt issuance costs (19,812 ) (11,307 ) Total debt, net $ 970,926 $ 1,126,303 Less: current portion of long-term debt 263,502 138,903 Total long-term debt $ 707,424 $ 987,400

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Contractual Override, Note Receivable and Long-Term Debt	The following table (in thousands) shows the carrying amount and estimated fair value of the Partnership's debt and contracts receivable—affiliate: March 31, 2017 December 31, 2016 Carrying Value Estimated Carrying Estimated Debt: NRP 2018 Senior Notes (1) $ 183,518 $ 187,358 $ 420,097 $ 412,250 NRP 2022 Senior Notes (1) 336,669 357,735 — — Opco Senior Notes and utility local improvement obligation (2) 459,288 479,124 500,174 488,814 Opco Revolving Credit Facility (3) — — 206,032 210,000 Assets: Contracts receivable—affiliate, current and long-term(2) 46,118 32,049 46,742 32,554 (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 outstanding borrowing 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. Fair Value—Recurring Warrants entered into in March 2017 are reported on the Partnership's consolidated balance sheets as a liability at Level 3 fair value using a binomial lattice model under the option pricing method. This model incorporates transaction details such as contractual terms, the Partnership’s common unit price, risk free interest rate, dividend yield and volatility. A significant decrease in the volatility or a significant decrease in the Partnership’s unit price, in isolation, would result in a significantly lower fair value measurement, and vice versa. The Warrants' binomial lattice model utilized the following assumptions on the following dates (fair value in thousands): Warrant Valuation Model Key Assumptions March 2, 2017 March 31, 2017 Closing price of NRP common units $ 41.95 $ 36.15 Risk-free interest rate 2.38 % 2.28 % Expected dividend yield 4.29 % 4.98 % Expected volatility 45.00 % 47.50 % The Warrants are recorded as non-current liabilities on the Partnership's consolidated balance sheets. Changes in the estimated fair value of the Warrants result in the recognition of other income or expense. The following table (in thousands) sets forth a summary of the beginning and ending balance sheet amounts and the changes in fair value of the Partnership's Level 3 Warrant liabilities that are measured at fair value on a recurring basis: Three Months Ended March 31, 2017 2016 Beginning balance $ — $ — Issuance of new Warrants 77,986 — Fair value adjustments for Warrant liabilities (16,569 ) — Ending balance (1) $ 61,417 $ — (1) During the three months ended March 31, 2017, there were no transfers in or out of Level 3 from other levels in the fair value hierarchy. NRP has embedded derivatives in the Preferred Units related to certain conversion options, redemption features and the change of control provision that are accounted for separately from the Preferred Units as assets and liabilities at fair value in NRP's consolidated balance sheets. Level 3 valuation of the embedded derivatives are based on numerous factors including the likelihood of the event occurring. The embedded derivatives are revalued quarterly, and changes in their fair value would be recorded in other income (expense) in NRP's consolidated statements of comprehensive income. The embedded derivatives had zero value at inception and as of March 31, 2017.
Schedule of Warrant Liability Assumption Inputs	The Warrants' binomial lattice model utilized the following assumptions on the following dates (fair value in thousands): Warrant Valuation Model Key Assumptions March 2, 2017 March 31, 2017 Closing price of NRP common units $ 41.95 $ 36.15 Risk-free interest rate 2.38 % 2.28 % Expected dividend yield 4.29 % 4.98 % Expected volatility 45.00 % 47.50 %
Summary of Warrants Outstanding	The following table (in thousands) sets forth a summary of the beginning and ending balance sheet amounts and the changes in fair value of the Partnership's Level 3 Warrant liabilities that are measured at fair value on a recurring basis: Three Months Ended March 31, 2017 2016 Beginning balance $ — $ — Issuance of new Warrants 77,986 — Fair value adjustments for Warrant liabilities (16,569 ) — Ending balance (1) $ 61,417 $ — (1) During the three months ended March 31, 2017, there were no transfers in or out of Level 3 from other levels in the fair value hierarchy.

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Summary of Reimbursements	Three Months Ended March 31, 2017 2016 Operating and maintenance expenses—affiliates, net 2,135 2,776 General and administrative—affiliates 1,124 937

Major Customers (Tables)

Major Customers (Tables)	3 Months Ended
	Mar. 31, 2017
Risks and Uncertainties [Abstract]
Major customers	Revenues from customers that exceeded ten percent of total revenues and other income for any of the periods presented below are as follows (in thousands except for percentages): Three Months Ended March 31, 2017 2016 Revenues Percent Revenues Percent Foresight Energy (1) $ 15,791 17.8 % $ 10,078 10.5 %

Unit-Based Compensation (Tables

Unit-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Activity in Outstanding Grants	A summary of activity in the outstanding grants during 2017 is as follows (in thousands): Phantom Units Outstanding grants at January 1, 2017 86 Grants vested and paid during the period (26 ) Forfeitures during the period (4 ) Outstanding grants at March 31, 2017 56

Cash Distributions (Tables)

Cash Distributions (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Schedule of distributions paid	The following table shows the distributions paid by the Partnership during the three months ended March 31, 2017 and 2016: Total Distributions (In thousands) Date Paid Period Covered by Distribution Distribution per Common Unit Common Units GP Interest Total 2017 February 14, 2017 October 1 - December 31, 2016 $ 0.45 $ 5,503 $ 112 $ 5,615 2016 February 12, 2016 October 1 - December 31, 2015 $ 0.45 $ 5,503 $ 113 $ 5,616

Deferred Revenue and Deferred40

Deferred Revenue and Deferred Revenue - Affiliate (Tables)	3 Months Ended
	Mar. 31, 2017
Deferred Revenue Disclosure [Abstract]
Schedule of Deferred Revenue	The Partnership recognized the following amounts of deferred revenue (including affiliate) attributable to previously paid minimums resulting from the expiration of the lessee’s ability to recoup the payments as Coal royalty and other revenue (in thousands): Three Months Ended March 31, 2017 2016 Coal royalty and other $ 758 $ 6,094 Coal royalty and other—affiliates 4,438 870 Total coal royalty and other (including affiliates) $ 5,196 $ 6,964 The Partnership’s deferred revenue (including affiliate) consist of the following (in thousands): March 31, 2017 December 31, 2016 Deferred revenue $ 46,008 $ 44,931 Deferred revenue—affiliate 68,735 71,632 Total deferred revenue (including affiliate) $ 114,743 $ 116,563

Basis of Presentation (Details)

Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	$ 20,205	$ 26,660
Net cash provided by (used in) investing activities	(2,039)	38,816
Net cash provided by (used in) financing activities	$ (54,408)	65,152
Classification of Cash Flow Items
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		7,200
Net cash provided by (used in) investing activities		800
Net cash provided by (used in) financing activities		$ 8,000

Convertible Preferred Units a42

Convertible Preferred Units and Warrants - Narrative (Details) - USD ($)	Apr. 25, 2017	Mar. 02, 2017	Mar. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Preferred Units, Cumulative Cash Distributions			$ 0
Preferred units issued and outstanding (in shares)			250,000	0
Preferred unit purchase price			$ 1,000	$ 0
Earnings attributable to Preferred Unitholders			$ 2,500,000
Preferred stock dividends excluded from earnings per share			$ 2,500,000
Class A Convertible Preferred Units [Member]
Class of Stock [Line Items]
Preferred units issued and outstanding (in shares)		250,000
Preferred unit purchase price		$ 1,000
Preferred Units, Origination Fee, Percent		2.50%
Dividend rate (as a percent)		12.00%
Convertible Preferred Units, Redemption Price, Minimum		$ 51
Convertible Preferred Units, Maximum Redeemed Units, Percent		33.00%
Debt Instrument, Covenants, Consolidated Leverage Ratio, Minimum		3.25
Debt Instrument, Covenants, Distributable Cash Flow Ratio, Maximum		1.2
Distribution amount (in dollars per share)		$ 0.45
Preferred preferred unitholder threshold (as a percent)		20.00%
Warrants at $22.81 Strike [Member] | Warrant [Member]
Class of Stock [Line Items]
Class of Warrant or Right, Warrants Issued		1,750,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 22.81
Warrants at $34.00 Strike [Member] | Warrant [Member]
Class of Stock [Line Items]
Class of Warrant or Right, Warrants Issued		2,250,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 34
Debt Instrument, Redemption, Period One | Class A Convertible Preferred Units [Member]
Class of Stock [Line Items]
Convertible Preferred Units, Conversion to Common Units, Discount Percentage		7.50%
Convertible Preferred Units, Purchase Price Multiplier		1.50
Debt Instrument, Redemption, Period Two | Class A Convertible Preferred Units [Member]
Class of Stock [Line Items]
Convertible Preferred Units, Conversion to Common Units, Discount Percentage		10.00%
Convertible Preferred Units, Purchase Price Multiplier		1.70
Debt Instrument, Redemption, Period Three | Class A Convertible Preferred Units [Member]
Class of Stock [Line Items]
Convertible Preferred Units, Conversion to Common Units, Discount Percentage		10.00%
Convertible Preferred Units, Purchase Price Multiplier		1.85
Preferred Stock
Class of Stock [Line Items]
Transaction price, gross		$ 250,000,000
Subsequent Event
Class of Stock [Line Items]
Dividend rate (as a percent)	12.00%

Convertible Preferred Units a43

Convertible Preferred Units and Warrants Convertible Preferred Units and Warrants - Preferred Units and Warrants Issued (Details) - USD ($) $ in Thousands	Mar. 02, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Preferred Units, net		$ 159,292		$ 0
Warrant liabilities		77,986	$ 0
Issuance costs allocated to Warrants and expensed		(5,709)	$ 0
Preferred Stock
Class of Stock [Line Items]
Transaction price, gross	$ 250,000
Structuring, origination and other fees to Preferred Purchasers	(7,900)
Transaction costs to other third parties	(10,531)
Transaction price, net	231,569
Preferred Units, net	159,292	$ 159,292
Warrant liabilities	77,986
Issuance costs allocated to Warrants and expensed	$ (5,709)

Convertible Preferred Units a44

Convertible Preferred Units and Warrants Convertible Preferred Units and Warrants - Financial Position (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 02, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Preferred Units, net	$ 159,292		$ 0
Warrant liabilities	61,417		$ 0	$ 0	$ 0
Preferred Stock
Class of Stock [Line Items]
Preferred Units, net	$ 159,292	$ 159,292

Net Income Per Limited Unit N45

Net Income Per Limited Unit Net Income Per Limited Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Allocation of net income:
Net income from continuing operations	$ 16,971	$ 26,351
Net income from continuing operations attributable to the general partner	220	461
Income attributable to preferred unitholders	2,500	0
Net income from continuing operations attributable to common unitholders	14,251	25,890
Net loss from discontinued operations	(207)	(2,924)
Net loss from discontinued operations attributable to the general partner	(4)	(58)
Net loss from discontinued operations attributable to common unitholders	(203)	(2,866)
Net Income	16,764	23,427
Net income attributable to the general partner	216	403
Net income attributable to common unitholders	$ 14,048	$ 23,024
Basic Income (Loss) per Unit:
Weighted average number of common units outstanding (in shares)	12,232	12,232
Basic net income (loss) per common unit from continuing operations (in dollars per share)	$ 1.17	$ 2.12
Basic net loss from discontinued operations per common unit (in dollars per share)	(0.02)	(0.23)
Basic net income per common unit (in dollars per share)	$ 1.15	$ 1.88
Diluted Income (Loss) per Unit:
Dilutive effect of Warrants (in shares)	322	0
Dilutive effect of Preferred Units (in shares)	2,391	0
Weighted average common units—diluted (in shares)	14,945	12,232
Dilutive effect of other income from Warrant liability fair value adjustments	$ (16,237)	$ 0
Diluted net income from continuing operations attributable to common unitholders	514	25,890
Diluted net loss from discontinued operations attributable to common unitholders	(203)	(2,866)
Diluted net income attributable to common unitholders	$ 311	$ 23,024
Diluted net income (loss) per common unit from discontinued operations (in dollars per share)	$ 0.03	$ 2.12
Diluted net loss from discontinued operations per common unit (in dollars per share)	(0.01)	(0.23)
Diluted net income per common unit (in dollars per share)	$ 0.02	$ 1.88

Segment Information - Additiona

Segment Information - Additional Information (Details) - segment	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Number of operating segments	3
Ciner Wyoming
Segment Reporting Information [Line Items]
Percentage of partnership interest owned (percent)	49.00%	49.00%

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues and other income	$ 88,653	$ 73,901
Gain on asset sales, net	44	21,925
Operating and maintenance expenses (including affiliates)	32,183	30,269
General and administrative (including affiliates)	7,202	4,172
Depreciation, depletion and amortization (including affiliates)	10,492	10,502
Asset impairments	1,778	1,893
Other expense, net	20,071	22,639
Net income (loss) from continuing operations	16,971	26,351
Net income (loss) from discontinued operations	(207)	(2,924)
Total assets	1,509,250		$ 1,444,681
Corporate and Financing
Segment Reporting Information [Line Items]
Revenues and other income	0	0
Gain on asset sales, net	0	0
Operating and maintenance expenses (including affiliates)	0	0
General and administrative (including affiliates)	7,202	4,172
Depreciation, depletion and amortization (including affiliates)	0	0
Asset impairments	0	0
Other expense, net	19,676	22,639
Net income (loss) from continuing operations	(26,878)	(26,811)
Net income (loss) from discontinued operations	0	0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues and other income	0	0
Coal Royalty and Other
Segment Reporting Information [Line Items]
Revenues and other income	34,994	28,849
Coal Royalty and Other | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	51,138	39,418
Gain on asset sales, net	29	21,925
Operating and maintenance expenses (including affiliates)	7,384	8,113
General and administrative (including affiliates)	0	0
Depreciation, depletion and amortization (including affiliates)	6,973	6,940
Asset impairments	1,778	1,893
Other expense, net	0	0
Net income (loss) from continuing operations	35,094	44,418
Net income (loss) from discontinued operations	0	0
Coal Royalty and Other | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues and other income	62	21
Soda Ash
Segment Reporting Information [Line Items]
Revenues and other income	10,294	9,801
Soda Ash | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	10,294	9,801
Gain on asset sales, net	0	0
Operating and maintenance expenses (including affiliates)	0	0
General and administrative (including affiliates)	0	0
Depreciation, depletion and amortization (including affiliates)	0	0
Asset impairments	0	0
Other expense, net	0	0
Net income (loss) from continuing operations	10,294	9,801
Net income (loss) from discontinued operations	0	0
Soda Ash | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues and other income	0	0
VantaCore
Segment Reporting Information [Line Items]
Revenues and other income	27,221	24,682
VantaCore | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	27,221	24,682
Gain on asset sales, net	15	0
Operating and maintenance expenses (including affiliates)	24,799	22,156
General and administrative (including affiliates)	0	0
Depreciation, depletion and amortization (including affiliates)	3,519	3,562
Asset impairments	0	0
Other expense, net	(395)	0
Net income (loss) from continuing operations	(1,539)	(1,057)
Net income (loss) from discontinued operations	0	0
VantaCore | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues and other income	(62)	$ (21)
Continuing Operations
Segment Reporting Information [Line Items]
Total assets	1,508,258		1,443,690
Continuing Operations | Corporate and Financing
Segment Reporting Information [Line Items]
Total assets	111,434		7,002
Continuing Operations | Coal Royalty and Other | Operating Segments
Segment Reporting Information [Line Items]
Total assets	956,782		990,172
Continuing Operations | Soda Ash | Operating Segments
Segment Reporting Information [Line Items]
Total assets	252,803		255,901
Continuing Operations | VantaCore | Operating Segments
Segment Reporting Information [Line Items]
Total assets	187,239		190,615
Discontinued Operations
Segment Reporting Information [Line Items]
Total assets	991		991
Discontinued Operations | Corporate and Financing
Segment Reporting Information [Line Items]
Total assets	0		0
Discontinued Operations | Coal Royalty and Other | Operating Segments
Segment Reporting Information [Line Items]
Total assets	0		0
Discontinued Operations | Soda Ash | Operating Segments
Segment Reporting Information [Line Items]
Total assets	0		0
Discontinued Operations | VantaCore | Operating Segments
Segment Reporting Information [Line Items]
Total assets	$ 0		$ 0

Discontinued Operations Summary

Discontinued Operations Summary of Financial Results of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Jul. 31, 2016
Assets
Total current assets	$ 991		$ 991
Liabilities
Total current liabilities	304		353
Discontinued Operations, Held-for-sale
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Oil and gas revenues and other income	15	$ 6,925
Loss on asset sales	(79)	0
Total revenues and other income	(64)	6,925
Operating and maintenance expenses (including affiliates)	143	4,381
Depreciation, depletion and amortization	0	4,241
Asset impairments	0	137
Total operating expenses	143	8,759
Interest expense	0	(1,090)
Loss from discontinued operations	(207)	(2,924)
Assets
Accounts receivable, net (including affiliates)	991		991
Total current assets	991		991
Total assets of discontinued operations	991		991
Liabilities
Other (including affiliates)	304		353
Total current liabilities	304		353
Total liabilities of discontinued operations	304		$ 353
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash paid for interest	0	631
Plant, equipment and mineral rights funded with accounts payable or accrued liabilities	0	811
Capital expenditures, Discontinued Operations	$ 0	$ 1,900
Disposal Group, Including Discontinued Operation, Consideration				$ 116,100

Equity Investment - Additional

Equity Investment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Distributions from equity method Investment	$ 12,250	$ 12,250
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%		49.00%
Distributions from equity method Investment	$ 12,300	12,300
Increase in fair value of property, plant and equipment	$ 148,800		$ 150,000
Anadarko Holding Company | Ciner Wyoming
Schedule of Equity Method Investments [Line Items]
Equity Investment Contingent Consideration Paid		$ 7,200

Equity Investment - Schedule o

Equity Investment - Schedule of Summarized Financial Information of Unaudited Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Net Income	$ 16,764	$ 23,427
Current assets	195,257		$ 104,252
Current liabilities	305,049		188,017
Ciner Wyoming
Schedule of Equity Method Investments [Line Items]
Income allocation to NRP’s equity interests	11,480	10,996
Amortization of basis difference	(1,186)	(1,195)
Equity in earnings of unconsolidated investment	10,294	9,801
Sales	126,572	114,384
Gross profit	28,697	28,251
Net Income	23,428	$ 22,441
Current assets	142,218		134,616
Non-current assets	233,209		235,427
Current liabilities	52,452		55,396
Non-current liabilities	$ 110,655		$ 98,425

Plant and Equipment - Plant and

Plant and Equipment - Plant and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Plant and equipment at cost	$ 81,199	$ 79,171
Construction in process	573	557
Less accumulated depreciation	(33,193)	(30,285)
Total plant and equipment, net	$ 48,579	$ 49,443

Plant and Equipment - Additiona

Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation expense on plant and equipment	$ 3	$ 3.4

Mineral Rights - Mineral Rights

Mineral Rights - Mineral Rights (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	$ 1,367,048	$ 1,375,019
Accumulated Depletion	(471,977)	(466,827)
Net Book Value	895,071	908,192
Coal Mineral Rights
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	1,170,700	1,170,904
Accumulated Depletion	(425,378)	(420,032)
Net Book Value	745,322	750,872
Aggregate Mineral Rights
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	176,774	176,774
Accumulated Depletion	(40,093)	(39,056)
Net Book Value	136,681	137,718
Oil And Gas Mineral Rights
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	12,395	12,395
Accumulated Depletion	(6,506)	(6,289)
Net Book Value	5,889	6,106
Other Mineral Rights
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Carrying Value	7,179	14,946
Accumulated Depletion	0	(1,450)
Net Book Value	$ 7,179	$ 13,496

Mineral Rights - Additional Inf

Mineral Rights - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Total depletion and amortization expense on mineral interests	$ 6,600	$ 6,100
Assets held for sale	17,500		$ 0
Asset impairments	1,778	1,893
Proceeds from sale of oil and gas royalty properties	(548)	32,848
Gain on asset sales, net	44	21,925
Land
Assets held for sale	13,000
Other Mineral Rights
Assets held for sale	$ 4,500
Appalachian Basin
Proceeds from sale of oil and gas royalty properties		37,500
Gain on asset sales, net		20,300
Texas, Georgia, Tennessee
Gain on asset sales, net		1,600
Proceeds from sale of hard mineral reserves		$ 10,000

Intangible Assets (Including 55

Intangible Assets (Including Affiliate) - Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 5,227	$ 5,227
Less accumulated amortization	(2,162)	(1,991)
Total intangible assets, net	3,065	3,236
Affiliated Entity
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	81,109	81,109
Less accumulated amortization	(32,066)	(31,298)
Total intangible assets, net	$ 49,043	$ 49,811

Intangible Assets (Including 56

Intangible Assets (Including Affiliate) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Intangible Assets [Line Items]
Amortization expense—affiliate	$ 768	$ 722
Amortization expense	$ 200	$ 200

Debt - Long-Term Debt (Detail)

Debt - Long-Term Debt (Detail) - USD ($)	Mar. 31, 2017	Mar. 02, 2017	Dec. 31, 2016	Oct. 31, 2014	Sep. 30, 2013
Debt Instrument [Line Items]
Senior Note issue percentage		98.75%
Principal balance	$ 992,922,000		$ 1,138,932,000
Net unamortized debt discount	(2,184,000)		(1,322,000)
Net unamortized debt issuance costs	(19,812,000)		(11,307,000)
Total debt	970,926,000		1,126,303,000
Less - current portion of long term debt	263,502,000		138,903,000
Total long-term debt	707,424,000		987,400,000
NRP LP
Debt Instrument [Line Items]
Interest rate					9.125%
Floating rate revolving credit facility				$ 125,000,000	$ 300,000,000
Senior Note issue percentage				99.50%	99.007%
NRP LP | 10.5% senior notes, with semi-annual interest payments in March and September, maturing March 2022 [Member]
Debt Instrument [Line Items]
Principal balance	$ 345,638,000		0
NRP LP | Senior Notes Due Two Zero Two Two [Member]
Debt Instrument [Line Items]
Interest rate	9.125%
Senior Notes, Face Amount	$ 345,638,000
NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Interest rate	9.125%
Senior Notes, Face Amount	$ 425,000,000
Principal balance	184,362,000		425,000,000
Opco | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility	180,000,000
Principal balance	$ 0		210,000,000
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]
Interest rate	4.91%
Principal balance	$ 9,187,000		9,187,000
Opco | 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019 [Member]
Debt Instrument [Line Items]
Interest rate	8.38%
Principal balance	$ 42,686,000		64,029,000
Opco | 5.05% senior notes, with semi-annual interest payments in January and July, with annual principal payments in July, maturing in July 2020 [Member]
Debt Instrument [Line Items]
Interest rate	5.05%
Principal balance	$ 30,633,000		30,633,000
Opco | 5.55% senior notes, with semi-annual interest payments in June and December, with annual principal payments in June, maturing in June 2023 [Member]
Debt Instrument [Line Items]
Interest rate	5.55%
Principal balance	$ 18,825,000		18,825,000
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 [Member]
Debt Instrument [Line Items]
Interest rate	4.73%
Principal balance	$ 52,204,000		52,204,000
Opco | 5.82% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2024 [Member]
Debt Instrument [Line Items]
Interest rate	5.82%
Principal balance	$ 104,583,000		119,524,000
Opco | 8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024 [Member]
Debt Instrument [Line Items]
Interest rate	8.92%
Principal balance	$ 31,738,000		36,272,000
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 [Member]
Debt Instrument [Line Items]
Interest rate	5.03%
Principal balance	$ 134,035,000		134,035,000
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 [Member]
Debt Instrument [Line Items]
Interest rate	5.18%
Principal balance	$ 38,262,000		38,262,000
Opco | Utility Local Improvement Obligation Due March Two Zero Two One [Member]
Debt Instrument [Line Items]
Interest rate	5.31%
Principal balance	$ 769,000		$ 961,000
Senior Notes Offering Price Two [Member] | NRP LP | Senior Notes Due Two Zero Two Two [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility	$ 240,638,000
Senior Note issue percentage	100.00%
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%
Senior Notes Offering Price One [Member] | NRP LP | Senior Notes Due Two Zero Two Two [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility	$ 105,000,000
Senior Note issue percentage	98.75%
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%

Debt - Additional Information (

Debt - Additional Information (Detail)	Apr. 03, 2017USD ($)	Mar. 02, 2017USD ($)	Sep. 30, 2013USD ($)	Mar. 31, 2017USD ($)$ / shares	Mar. 31, 2016USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Apr. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Oct. 31, 2014USD ($)
Debt Instrument [Line Items]
Senior Note issue percentage		98.75%
Principal balance				$ 992,922,000					$ 1,138,932,000
Discount on debt issuance (as a percent)		1.25%
Debt Instrument, Net Redemption Premium, Percent		5.813%
Redemption fee (as a percent)		1.25%
Call premium (as a percent)		4.563%
Aggregate principal amount redeemable (as a percent)		35.00%
Senior Notes due 2022
Debt Instrument [Line Items]
Principal balance				336,669,000					0
Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Rate of senior notes		10.50%
Senior Notes, Face Amount		$ 346,000,000
Proceeds from issuance of secured debt		$ 105,000,000
Principal remaining after redemption (as a percent)		65.00%
Purchase price (as a percent)		101.00%
Senior Notes due 2018
Debt Instrument [Line Items]
Principal balance				$ 183,518,000					$ 420,097,000
Senior Notes due 2018 | Senior Notes
Debt Instrument [Line Items]
Senior Notes, Face Amount		$ 241,000,000
Ciner Wyoming
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)				49.00%					49.00%
Ciner Wyoming | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of partnership interest owned (percent)				49.00%
NRP LP
Debt Instrument [Line Items]
Rate of senior notes			9.125%
Floating rate revolving credit facility			$ 300,000,000							$ 125,000,000
Senior Note issue percentage			99.007%							99.50%
NRP LP | 9.125% senior notes, with semi-annual interest payments in April and October, maturing October 2018
Debt Instrument [Line Items]
Rate of senior notes				9.125%
Principal balance				$ 184,362,000					$ 425,000,000
Senior Notes, Face Amount				$ 425,000,000
NRP LP | Maximum
Debt Instrument [Line Items]
Fixed charge coverage ratio				2
NRP LP | Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio				1
Opco
Debt Instrument [Line Items]
Ratio of consolidated EBITDDA to consolidated fixed charges				3.5
Percentage of consolidated net tangible assets debt of subsidiaries not permitted to exceed				10.00%
Repayment of principal amount			$ 289,000,000
Opco | Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period				5.22%	3.80%
Commitment fee on the unused portion of the borrowing base under the credit facility (percent)				0.50%
Debt Instrument, Asset Sales Proceeds, Required to Repay Outstanding Debt, Percent				75.00%
Ratio of consolidated EBITDDA to consolidated fixed charges				3.5
Secured Debt				$ 660,700,000					673,000,000
Opco | 8.38% senior notes, with semi-annual interest payments in March and September, with annual principal payments in March, maturing in March 2019 [Member]
Debt Instrument [Line Items]
Rate of senior notes				8.38%
Principal balance				$ 42,686,000					64,029,000
Opco | 8.92% senior notes, with semi-annual interest payments in March and September, with scheduled principal payments beginning March 2014, maturing in March 2024 [Member]
Debt Instrument [Line Items]
Rate of senior notes				8.92%
Principal balance				$ 31,738,000					36,272,000
Opco | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Covenant, Asset Sales				$ 300,000,000
Debt Instrument, Asset Sales Proceeds, Required to Repay Outstanding Debt, Percent				25.00%
Principal balance				$ 462,200,000					503,000,000
Principal payments on its senior notes				$ (40,800,000)	$ (41,000,000)
Partnership leverage ratio				3.75
Additional interest accrue				2.00%
Opco | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility				$ 180,000,000
Principal balance				$ 0					$ 210,000,000
Opco | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Distribution amount (in dollars per share) | $ / shares				$ 0.45
Opco | Maximum
Debt Instrument [Line Items]
Ratio of consolidated indebtedness to consolidated EBITDDA				4
Opco | Scenario, Forecast [Member] | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Floating rate revolving credit facility						$ 100,000,000	$ 150,000,000
Opco | Federal Funds Rate [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)				0.50%
Opco | London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (percent)				1.00%
Opco | London Interbank Offered Rate (LIBOR) [Member] | Maximum | Revolving Credit Facility Basis Spread Condition One [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				3.50%
Opco | London Interbank Offered Rate (LIBOR) [Member] | Maximum | Revolving Credit Facility Basis Spread Condition Two [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				4.50%
Opco | London Interbank Offered Rate (LIBOR) [Member] | Minimum | Revolving Credit Facility Basis Spread Condition One [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				2.50%
Opco | London Interbank Offered Rate (LIBOR) [Member] | Minimum | Revolving Credit Facility Basis Spread Condition Two [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Additional basis spread (percent)				3.50%
Debt Instrument, Redemption, Period One | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)		110.50%
Debt Instrument, Redemption, Period Two | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)		105.25%
Debt Instrument, Redemption, Period Three | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)		102.625%
Debt Instrument, Redemption, Period Four | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)		100.00%
Restricted Payments Covenant | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Consolidated leverage ratio, maximum		4
Distribution limit (as a percent)		50.00%
Debt Incurrence Covenant | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Consolidated leverage ratio, maximum		3
Debt covenant, maximum debt		$ 150,000,000
Dividend at or Below $0.45 per Share | Opco | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Maximum leverage ratio		4		4
Dividend Above $0.45 per Share | Opco | Floating Rate Revolving Credit Facility Due April Two Thousand Twenty Two
Debt Instrument [Line Items]
Maximum leverage ratio				3
Subsequent Event | Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Debt redeemed								$ 346,000,000
Senior Notes, Face Amount								$ 346,000,000
Subsequent Event | Senior Notes due 2018 | Senior Notes
Debt Instrument [Line Items]
Debt redeemed	$ 90,000,000
Redemption price (as a percent)	104.563%

Fair Value Measurements - Contr

Fair Value Measurements - Contractual Override, Note Receivable and Long-Term Debt (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 992,922	$ 1,138,932
Contracts receivable—affiliate, current and long-term	46,118	46,742
Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contracts receivable—affiliate, current and long-term	32,049	32,554
Senior Notes due 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	183,518	420,097
Senior Notes due 2018 | Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	187,358	412,250
Senior Notes due 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	336,669	0
Senior Notes due 2022 | Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	357,735	0
Opco Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	459,288	500,174
Opco Senior Notes | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	479,124	488,814
Opco Revolving Credit Facility And Term Loan Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	0	206,032
Opco Revolving Credit Facility And Term Loan Facility | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	$ 0	$ 210,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Warrant Liability Assumption Inputs (Details) - $ / shares	Mar. 02, 2017	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Closing price of NRP common units (in dollars per share)	$ 41.95	$ 36.15
Risk-free interest rate (as a percent)	2.38%	2.28%
Expected dividend yield (as a percent)	4.29%	4.98%
Expected volatility (as a percent)	45.00%	47.50%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Warrants Outstanding (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 02, 2017
Equity [Abstract]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3	0
Embedded Derivative, Fair Value of Embedded Derivative Liability	0		$ 0
Preferred Stock Warrants Outstanding [Roll Forward]
Beginning balance	0	$ 0
Issuance of new Warrants	77,986,000	0
Fair value adjustments for Warrant liabilities	(16,569,000)	0
Ending balance	$ 61,417,000	$ 0

Related Party Transactions - Su

Related Party Transactions - Summary of Reimbursements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	$ 2,555	$ 3,484
General and administrative—affiliates	1,124	937
Affiliated Entity | Western Pocahontas Properties and Quintana Minerals Corporation [Member]
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	$ 2,135	$ 2,776

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Non-cash contributions	$ 70
Amount payable to related parties	1,196		$ 940
Operating and maintenance expenses—affiliates, net	2,555	$ 3,484
Revenues and other income	88,653	73,901
Unrecouped minimum royalty payments	68,700	71,600
Contracts receivable—affiliate, current and long-term	46,118		46,742
Accounts receivable—affiliates	7,605		6,658
General Partner
Related Party Transaction [Line Items]
Non-cash contributions	100	100
Quintana Minerals
Related Party Transaction [Line Items]
Amount payable to related parties	700		400
Operating and maintenance expenses—affiliates, net	0	300
Western Pocahontas Properties
Related Party Transaction [Line Items]
Amount payable to related parties	500		600
Cline Affiliates
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	$ 300	400
Rate of interest in the partnerships general partner	31.00%
Related party transaction number of units hold by the related party in partnerships' general partner	0.5
Accounts receivable—affiliates	$ 7,500		6,500
Net amount receivable			2,700
Accounts receivable—affiliates			1,400
Cline Affiliates
Related Party Transaction [Line Items]
Net amount receivable	2,700
Accounts receivable—affiliates	2,200
Foresight Energy Lp | Coal Sales
Related Party Transaction [Line Items]
Revenues and other income	15,800	10,100
Sugar Camp
Related Party Transaction [Line Items]
Contracts receivable—affiliate, current and long-term	75,200		76,400
Unearned income	30,900		31,800
Net amount receivable	44,200		44,600
Accounts receivable—affiliates	2,100		2,200
Corsa
Related Party Transaction [Line Items]
Accounts receivable—affiliates	100		200
Royalty Revenue from Coal	400	500
Western Pocahontas Properties Limited Partnership | Affiliated Entity
Related Party Transaction [Line Items]
Operating and maintenance expenses—affiliates, net	100	$ 600
Other assets—affiliate	1,000		1,000
Discontinued Operations, Held-for-sale | Quintana Minerals
Related Party Transaction [Line Items]
Amount payable to related parties	$ 0		$ 100

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Lawsuit Against Hillsboro Energy LLC
Commitments And Contingencies [Line Items]
Minimum quarterly deficiency payments	$ 7.5
Minimum deficiency payments	30
Loss contingency	53.5
Lawsuit Against Macoupin Energy, LLC
Commitments And Contingencies [Line Items]
Damages sought, value	$ 8

Major Customers (Detail)

Major Customers (Detail) - Foresight Energy Lp - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Concentration Risk [Line Items]
Revenues	$ 15,791	$ 10,078
Sales Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	17.80%	10.50%

Unit-Based Compensation Additio

Unit-Based Compensation Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of Grants (in years)	4 years
Incentive Fee Expense	$ 0.4	$ 0.1
Unaccrued Cost Associated With Outstanding Grants And Related Distribution Equivalent Rights	0.7		$ 0.8
General Partner
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments of Stock Issuance Costs	$ 1.7	$ 1.5
Phantom Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of trading days (in days)	20 days

Unit-Based Compensation Summary

Unit-Based Compensation Summary of Activity in Outstanding Grants (Details)	3 Months Ended
	Mar. 31, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding grants at beginning of period (in shares)	86,000
Grants vested and paid during the period (in shares)	(26,000)
Forfeitures during the period (in shares)	(4,000)
Outstanding grants at the end of the period (in shares)	56,000

Cash Distributions (Details)

Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 14, 2017	Feb. 12, 2016	Mar. 31, 2017	Mar. 31, 2016
Equity [Abstract]
Distribution per common unit (in dollars per share)	$ 0.45	$ 0.45
Distributions paid to common unitholders	$ 5,503	$ 5,503	$ 5,615	$ 5,616
Distributions paid to general partners	112	113
Total distributions paid	$ 5,615	$ 5,616	$ 5,615

Deferred Revenue and Deferred69

Deferred Revenue and Deferred Revenue - Affiliate Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 46,008		$ 44,931
Deferred revenue—affiliates	68,735		71,632
Deferred Revenue, Including Related Party	114,743		$ 116,563
Coal Royalty and Other
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Revenue Recognized	758	$ 6,094
Deferred Revenue, Revenue Recognized, Including Related Party	5,196	6,964
Coal Royalty and Other | Affiliated Entity
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Revenue Recognized	$ 4,438	$ 870

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	May 09, 2017	Apr. 25, 2017	Apr. 03, 2017	Feb. 14, 2017	Feb. 12, 2016	Mar. 31, 2017	Apr. 30, 2017	Mar. 02, 2017
Subsequent Event [Line Items]
Distribution paid (in dollar per share)				$ 0.45	$ 0.45
Senior Notes due 2018 | Senior Notes
Subsequent Event [Line Items]
Senior Notes, Face Amount								$ 241
Senior Notes due 2022 | Senior Notes
Subsequent Event [Line Items]
Senior Notes, Face Amount								$ 346
Subsequent Event
Subsequent Event [Line Items]
Distribution paid (in dollar per share)		$ 0.45
Dividend rate (as a percent)		12.00%
Preferred Stock, Shares Issued		1,250
Subsequent Event | Senior Notes due 2018 | Senior Notes
Subsequent Event [Line Items]
Debt redeemed			$ 90
Redemption price (as a percent)			104.563%
Subsequent Event | Senior Notes due 2022 | Senior Notes
Subsequent Event [Line Items]
Debt redeemed							$ 346
Senior Notes, Face Amount							$ 346
Cline Affiliates
Subsequent Event [Line Items]
Rate of interest in the partnerships general partner						31.00%
Cline Affiliates | Subsequent Event
Subsequent Event [Line Items]
Rate of interest in the partnerships general partner	31.00%
Great Northern Properties Limited Partnership [Member] | Subsequent Event
Subsequent Event [Line Items]
Rate of interest in the partnerships general partner	10.00%
Western Pocahontas Properties Limited Partnership | Subsequent Event
Subsequent Event [Line Items]
Rate of interest in the partnerships general partner	90.00%
GP Natural Resource Partners LLC (the general partner of NRP GP) [Member] | Subsequent Event
Subsequent Event [Line Items]
Rate of interest in the partnerships general partner	0.00%