Sisecam Resources (SIRE) 10-Q 5 Aug 19 2019 Q2 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - shares	6 Months Ended
	Jun. 30, 2019	Aug. 02, 2019
Document Information [Line Items]
Entity Registrant Name	Ciner Resources LP
Entity Central Index Key	0001575051
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q2
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Common Unitholders
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		19,738,407
General Partner
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		399,000

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 9.4	$ 10.2
Accounts receivable—affiliates	100.3	70.1
Accounts receivable, net	35.3	36.9
Inventory	22.4	22.3
Other current assets	2.1	2
Total current assets	169.5	141.5
Property, plant and equipment, net	282.7	266.7
Other non-current assets	26.9	26.4
Total assets	479.1	434.6
Current liabilities:
Accounts payable	14	17.6
Due to affiliates	3.9	2.6
Accrued expenses	33.8	44.4
Total current liabilities	51.7	64.6
Long-term debt	145.5	99
Other non-current liabilities	9.3	10.9
Total liabilities	206.5	174.5
Commitments and contingencies
Equity:
Common unitholders - Public and Ciner Holdings (19.7 units issued and outstanding at June 30, 2019 and December 31, 2018)	159.4	153.8
General partner unitholders - Ciner Resource Partners LLC (0.4 units issued and outstanding at June 30, 2019 and December 31, 2018)	4	3.9
Accumulated other comprehensive loss	(3.6)	(3.8)
Partners’ capital attributable to Ciner Resources LP	159.8	153.9
Non-controlling interest	112.8	106.2
Total equity	272.6	260.1
Total liabilities and partners’ equity	$ 479.1	$ 434.6

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares shares in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common units issued (in shares)	19.7	19.7
Common units outstanding (in shares)	19.7	19.7
General partner units issued (in shares)	0.4	0.4
General partner units outstanding (in shares)	0.4	0.4

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net Sales:
Sales—affiliates	$ 81.8	$ 49.6	$ 159.3	$ 115.5
Sales—others	48	60.3	100.9	115.6
Net sales	129.8	109.9	260.2	231.1
Operating costs and expenses:
Cost of products sold including freight costs (excludes depreciation, depletion and amortization expense set forth separately below)	90.6	88.7	180.8	175.1
Depreciation, depletion and amortization expense	6.9	7.3	13.2	14.1
Selling, general and administrative expenses—affiliates	5.3	4.3	10.8	9.2
Selling, general and administrative expenses—others	1.7	2.1	3.6	3.6
Litigation settlement	0	(27.5)	0	(27.5)
Total operating costs and expenses	104.5	74.9	208.4	174.5
Operating income	25.3	35	51.8	56.6
Other income (expenses):
Interest income	0.1	0.8	0.2	1.4
Interest expense	(1.6)	(1.2)	(3)	(2.5)
Other, net	0	(0.1)	0	(0.1)
Total other expense, net	(1.5)	(0.5)	(2.8)	(1.2)
Net income	23.8	34.5	49	55.4
Net income attributable to non-controlling interest	12.5	17.7	25.4	28.5
Net income attributable to Ciner Resources LP	11.3	16.8	23.6	26.9
Other comprehensive loss:
Income/(loss) on derivative financial instruments	(1.6)		0.4
Income/(loss) on derivative financial instruments		(1)		(3.2)
Comprehensive income	22.2	33.5	49.4	52.2
Comprehensive income attributable to non-controlling interest	11.7	17.2	25.6	26.9
Comprehensive income attributable to Ciner Resources LP	$ 10.5	$ 16.3	$ 23.8	$ 25.3
Net income per limited partner unit:
Common - Public and Ciner Holdings (basic and diluted) (dollars per share)	$ 0.56	$ 0.83	$ 1.17	$ 1.34
Limited partner units outstanding:
Weighted average common units outstanding (basic and diluted) (shares)	19.7	19.7	19.7	19.7

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 49	$ 55.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization expense	13.3	14.3
Litigation settlement	0	(27.5)
Equity-based compensation expenses	1	1
Other non-cash items	0.2	0.1
Changes in operating assets and liabilities:
Accounts receivable—affiliates	(30.2)	22.8
Accounts receivable, net	1.6	(7.9)
Inventory	(0.3)	(1.5)
Other current and non current assets	0	(0.1)
Increase (decrease) in:
Accounts payable	(3.8)	(0.6)
Due to affiliates	1.3	1
Accrued expenses and other liabilities	(4.1)	0.2
Net cash provided by operating activities	28	57.2
Cash flows from investing activities:
Capital expenditures	(37.5)	(14.9)
Net cash used in investing activities	(37.5)	(14.9)
Cash flows from financing activities:
Borrowings on Ciner Wyoming credit facility	90	55
Repayments on Ciner Wyoming credit facility	(43.5)	(59)
Common units surrendered for taxes	(0.5)	(0.3)
Distributions to non-controlling interest	(19)	(24.5)
Net cash provided by (used in) financing activities	8.7	(51.6)
Net decrease in cash and cash equivalents	(0.8)	(9.3)
Cash and cash equivalents at beginning of period	10.2	30.2
Cash and cash equivalents at end of period	9.4	20.9
Common Unitholders
Cash flows from financing activities:
Distributions	(17.9)	(22.3)
General Partner
Cash flows from financing activities:
Distributions	$ (0.4)	$ (0.5)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Accumulated Other Comprehensive Loss	Partners’ Capital Attributable to Ciner Resources LP Equity	Non-controlling Interest	Common UnitholdersPartnership units	General PartnerPartnership units
Beginning balance at Dec. 31, 2017	$ 248.2	$ (3.7)	$ 148.4	$ 99.8	$ 148.3	$ 3.8
Increase (decrease) in shareholders' equity
Net income	20.9		10.1	10.8	9.9	0.2
Other comprehensive income/(loss)	(2.2)	(1.1)	(1.1)	(1.1)
Equity-based compensation plan activity	(0.1)		(0.1)		(0.1)
Distributions	(23.6)		(11.3)	(12.3)	(11.1)	(0.2)
Ending balance at Mar. 31, 2018	243.2	(4.8)	146	97.2	147	3.8
Beginning balance at Dec. 31, 2017	248.2	(3.7)	148.4	99.8	148.3	3.8
Increase (decrease) in shareholders' equity
Net income	55.4
Ending balance at Jun. 30, 2018	253.6	(5.3)	151.4	102.2	152.9	3.8
Beginning balance at Mar. 31, 2018	243.2	(4.8)	146	97.2	147	3.8
Increase (decrease) in shareholders' equity
Net income	34.5		16.8	17.7	16.5	0.3
Other comprehensive income/(loss)	(1)	(0.5)	(0.5)	(0.5)
Equity-based compensation plan activity	0.6		0.6		0.6
Distributions	(23.7)		(11.5)	(12.2)	(11.2)	(0.3)
Ending balance at Jun. 30, 2018	253.6	(5.3)	151.4	102.2	152.9	3.8
Beginning balance at Dec. 31, 2018	260.1	(3.8)	153.9	106.2	153.8	3.9
Increase (decrease) in shareholders' equity
Net income	25.2		12.3	12.9	12.1	0.2
Other comprehensive income/(loss)	2	1	1	1
Equity-based compensation plan activity	(0.3)		(0.3)		(0.3)
Distributions	(21.1)		(11.3)	(9.8)	(11.1)	(0.2)
Ending balance at Mar. 31, 2019	265.9	(2.8)	155.6	110.3	154.5	3.9
Beginning balance at Dec. 31, 2018	260.1	(3.8)	153.9	106.2	153.8	3.9
Increase (decrease) in shareholders' equity
Net income	49
Ending balance at Jun. 30, 2019	272.6	(3.6)	159.8	112.8	159.4	4
Beginning balance at Mar. 31, 2019	265.9	(2.8)	155.6	110.3	154.5	3.9
Increase (decrease) in shareholders' equity
Net income	23.8		11.3	12.5	11	0.3
Other comprehensive income/(loss)	(1.6)	(0.8)	(0.8)	(0.8)
Equity-based compensation plan activity	0.7		0.7		0.7
Distributions	(16.2)		(7)	(9.2)	(6.8)	(0.2)
Ending balance at Jun. 30, 2019	$ 272.6	$ (3.6)	$ 159.8	$ 112.8	$ 159.4	$ 4

CORPORATE STRUCTURE AND SUMMARY

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations The unaudited condensed consolidated financial statements are composed of Ciner Resources LP (the “Partnership,” “CINR,” “Ciner Resources,” “we,” “us,” or “our”), a publicly traded Delaware limited partnership, and its consolidated subsidiary, Ciner Wyoming LLC (“Ciner Wyoming”), which is in the business of mining trona ore to produce soda ash. The Partnership’s operations consist solely of its investment in Ciner Wyoming. The Partnership was formed in April 2013 by Ciner Wyoming Holding Co. (“Ciner Holdings”), a wholly-owned subsidiary of Ciner Resources Corporation (“Ciner Corp”). Ciner Corp is a direct wholly-owned subsidiary of Ciner Enterprises Inc. (“Ciner Enterprises”), which is a direct wholly-owned subsidiary of WE Soda Ltd., a U.K. corporation (“WE Soda”). WE Soda is a direct wholly-owned subsidiary of KEW Soda Ltd., a U.K. corporation (“KEW Soda”), which is a direct wholly-owned subsidiary of Akkan Enerji ve Madencilik Anonim Şirketi (“Akkan”). Akkan is directly and wholly owned by Turgay Ciner, the Chairman of the Ciner Group (“Ciner Group”), a Turkish conglomerate of companies engaged in energy and mining (including soda ash mining), media and shipping markets. The Partnership owns a controlling interest comprised of 51.0% membership interest in Ciner Wyoming. All of our soda ash processed is currently sold to various domestic and international customers, including ANSAC which is an affiliate for export sales. Basis of Presentation and Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applicable to interim period financial statements and reflect all adjustments, consisting of normal recurring accruals, which are necessary for fair presentation of the results of operations, financial position and cash flows for the periods presented. All intercompany transactions, balances, revenue and expenses have been eliminated in consolidation. The results of operations for the six months ended June 30, 2019 and 2018 are not necessarily indicative of the operating results for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes to audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 (the “ 2018 Annual Report”). As of January 1, 2019, we have adopted the guidance outlined in Accounting Standards Codification (“ASC”) Standard 842, Leases (“ASC 842”). For further information on the Partnership’s adoption of this standard, refer to “Recently Issued Accounting Pronouncements” below. There have been no other material changes in the significant accounting policies followed by us during the six month period ended June 30, 2019 from those disclosed in the 2018 Annual Report. Non-controlling interests NRP Trona LLC, a wholly-owned subsidiary of Natural Resource Partners L.P. ("NRP"), currently owns a 49.0% membership interest in Ciner Wyoming. Use of Estimates The preparation of these unaudited condensed consolidated financial statements, in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the dates of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Subsequent Events We have evaluated subsequent events through the filing date of this Quarterly Report on Form 10-Q. Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) to increase the transparency and comparability about leases among entities. Additional ASUs have been issued subsequent to ASU 2016-02 to provide supplementary clarification and implementation guidance for leases related to, among other things, the application of certain practical expedients, the rate implicit in the lease, lessee reassessment of lease classification, lessor reassessment of lease term and purchase options, variable payments that depend on an index or rate and certain transition adjustments. ASU 2016-02 and these additional ASUs are now codified as ASC 842. Pursuant to these updates, accounting for leases by lessors remains largely unchanged from current guidance. The update requires that lessees recognize a lease liability and a right of use asset for all leases (with the exception of short-term leases) at the commencement date of the lease and disclose key information about leasing arrangements. For leases less than 12 months, an entity is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The Partnership made this election upon adoption. In preparation for the new requirements, the Partnership completed its evaluation of the lease agreements during 2018. The Partnership adopted ASC 842 effective January 1, 2019 using a modified retrospective approach under which prior comparative periods will not be adjusted, as permitted by the guidance. The Partnership has determined that the adoption of the new standard did not have a material impact on the balance sheet or statement of operations because the Partnership has no material long term leases that are subject to ASC 842. Ciner Corp was determined to be the ultimate lessee for rail car lease agreements under ASC 842, and the Partnership will continue to incur an allocation of rent expense in relation to the use of rail cars leased by Ciner Corp. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (“ASU Topic 815”) – Targeted Improvements to Accounting for Hedging Activities. ASU Topic 815 aims to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, ASU Topic 815 makes certain targeted improvements to simplify the application of the existing hedge accounting guidance. ASU Topic 815 is effective for us beginning in the first quarter of 2019, with early application permitted. The Partnership adopted ASU Topic 815 effective January 1, 2019 and concluded there is no material impact to the Partnership’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, “Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force)” (“ASU 2018-15”), which amends ASC 350-40 to address a customer’s accounting for implementation costs incurred in a cloud computing arrangement (“CCA”) that is a service contract. ASU 2018-15 amends ASC 350 and clarifies that a customer should apply ASC 350-40 to determine which implementation costs should be capitalized in a CCA. The ASU does not expand on existing disclosure requirements except to require a description of the nature of hosting arrangements that are service contracts. Entities are permitted to apply either a retrospective or prospective transition approach to adopt the guidance. The Partnership is currently evaluating the potential impact this will have on the Partnership’s consolidated financial statements.

NET INCOME PER UNIT AND CASH DI

NET INCOME PER UNIT AND CASH DISTRIBUTION	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
NET INCOME PER UNIT AND CASH DISTRIBUTION	NET INCOME PER UNIT AND CASH DISTRIBUTION Allocation of Net Income Net income per unit applicable to limited partners is computed by dividing limited partners’ interest in net income attributable to Ciner Corp, after deducting the general partner’s interest and any incentive distributions, by the weighted average number of outstanding common units. Our net income is allocated to the general partner and limited partners in accordance with their respective partnership percentages, after giving effect to priority income allocations for incentive distributions, if any, to our general partner, pursuant to our partnership agreement. Earnings in excess of distributions are allocated to the general partner and limited partners based on their respective ownership interests. Payments made to our unitholders are determined in relation to actual distributions declared and are not based on the net income allocations used in the calculation of net income per unit. In addition to the common units, we have also identified the general partner interest and incentive distribution rights (“IDRs”) as participating securities and use the two-class method when calculating the net income per unit applicable to limited partners, which is based on the weighted-average number of common units outstanding during the period. Potentially dilutive and anti-dilutive units outstanding were immaterial for both the three and six months ended June 30, 2019 and 2018 . The net income attributable to limited partner unitholders and the weighted average units for calculating basic and diluted net income per limited partner units were as follows: Three Months Ended Six Months Ended (In millions, except per unit data) 2019 2018 2019 2018 Numerator: Net income attributable to Ciner Resources LP $ 11.3 $ 16.8 $ 23.6 $ 26.9 Less: General partner’s interest in net income 0.3 0.3 0.5 0.5 Total limited partners’ interest in net income $ 11.0 $ 16.5 $ 23.1 $ 26.4 Denominator: Weighted average limited parter units outstanding: Weighted average common units outstanding (basic and diluted) 19.7 19.7 19.7 19.7 Net income per limited partner units: Net income per limited partner units (basic and diluted) $ 0.56 $ 0.83 $ 1.17 $ 1.34 The calculation of limited partners’ interest in net income is as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Net income attributable to common unitholders: Distributions (1) $ 6.7 $ 11.2 $ 13.4 $ 22.3 Undistributed earnings (Distributions in excess) of net income 4.3 5.3 9.7 4.1 Common unitholders’ interest in net income $ 11.0 $ 16.5 $ 23.1 $ 26.4 (1) Distributions declared per common unit for the period $ 0.340 $ 0.567 $ 0.680 $ 1.134 Quarterly Distribution Declared On July 30, 2019 , the Partnership declared its second quarter 2019 quarterly cash distribution of $0.340 per unit. The quarterly cash distribution is payable on August 28, 2019 to unitholders of record on August 9, 2019 . While we are working on finalizing our capital plans for a new expansion project that we believe will significantly increase production levels up to approximately 3.5 million tons of soda ash per year, such plans will require capital expenditures materially higher than have been incurred by Ciner Wyoming in recent years. To maintain a disciplined financial policy and what we believe is a conservative capital structure we intend to pay for the investment in part through cash generated by the business and in part through debt. When considering the significant investment required by this expansion and the infrastructure improvements designed to increase our overall efficiency, beginning with the quarter ended March 31, 2019, we lowered our quarterly cash distributions from Ciner Wyoming and the Partnership to $0.340 per unit to satisfy approximately 50% of the funding for the project, which we believe will be for approximately 9-11 quarters depending upon business performance. Subject to our business performance, we intend to maintain the distribution at this level until such targets are met. Our general partner has considerable discretion in determining the amount of available cash, the amount of distributions and the decision to make any distribution. Although our partnership agreement requires that we distribute all of our available cash quarterly, there is no guarantee that we will make quarterly cash distributions to our unitholders at our current quarterly distribution level, at the minimum quarterly distribution level or at any other rate, and we have no legal obligation to do so. General Partner Interest and Incentive Distribution Rights Our partnership agreement provides that our general partner initially will be entitled to 2.0% of all distributions that we make prior to our liquidation. Our general partner has the right, but not the obligation, to contribute up to a proportionate amount of capital to us in order to maintain its 2.0% general partner interest if we issue additional units (other than the issuance of common units upon a reset of the IDRs). Our general partner currently has an approximate 2.0% ownership interest in the partnership. Our partnership agreement does not require that our general partner fund its capital contribution with cash. It may, instead, fund its capital contribution by contributing to us common units or other property. IDRs represent the right to receive increasing percentages ( 13.0% , 23.0% and 48.0% ) of quarterly distributions from operating surplus after we have achieved the minimum quarterly distribution and the target distribution levels. Our general partner currently holds the IDRs, but may transfer these rights separately from its general partner interest, subject to certain restrictions in our partnership agreement. Percentage Allocations of Distributions from Operating Surplus The following table illustrates the percentage allocations of distributions from operating surplus between the unitholders and our general partner based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of our general partner and the unitholders in any distributions from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution per Unit Target Amount.” The percentage interests shown for our unitholders and our general partner for the minimum quarterly distribution also apply to quarterly distribution amounts that are less than the minimum quarterly distribution, including for the declared quarterly distributions of $0.340 per unit for the second quarter of 2019. Other than the requirement in our partnership agreement to distribute all of our available cash (as defined there) each quarter, the partnership agreement of the Partnership does not contain a requirement for the Partnership to pay any quarterly cash distributions to its unitholders, and our general partner has considerable discretion to establish cash reserves that would reduce the amount of available cash we distribute to unit holders. The Partnership does not guarantee that it will pay the target amount of the minimum quarterly distribution listed below (or any distributions) on its units in any quarter. The percentage interests set forth below for our general partner (1) include its 2.0% general partner interest, (2) assume that our general partner has contributed any additional capital necessary to maintain its 2.0% general partner interest, (3) assume that our general partner has not transferred its IDRs and (4) assume there are no arrearages on common units. Marginal Percentage Interest in Distributions Total Quarterly Distribution per Unit Target Amount Unitholders General Partner Minimum Quarterly Distribution $0.5000 98.0 % 2.0 % First Target Distribution above $0.5000 up to $0.5750 98.0 % 2.0 % Second Target Distribution above $0.5750 up to $0.6250 85.0 % 15.0 % Third Target Distribution above $0.6250 up to $0.7500 75.0 % 25.0 % Thereafter above $0.7500 50.0 % 50.0 %

INVENTORY

INVENTORY	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory consisted of the following: As of (In millions) June 30, December 31, Raw materials $ 10.7 $ 10.9 Finished goods 6.0 5.1 Stores inventory 5.7 6.3 Total $ 22.4 $ 22.3

DEBT

DEBT	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
DEBT	DEBT Long-term debt consisted of the following: As of (In millions) June 30, December 31, Ciner Wyoming Credit Facility, unsecured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 3.91% and 3.99% at June 30, 2019 and December 31, 2018, respectively $ 145.5 $ 99.0 Total debt 145.5 99.0 Current portion of long-term debt — — Total long-term debt $ 145.5 $ 99.0 Aggregate maturities required on long-term debt at June 30, 2019 are due in future years as follows: (In millions) Amount 2021 $ — 2022 145.5 2023 to 2025 and beyond — Total $ 145.5

OTHER NON-CURRENT LIABILITIES

OTHER NON-CURRENT LIABILITIES	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation Disclosure [Abstract]
OTHER NON-CURRENT LIABILITIES	OTHER NON-CURRENT LIABILITIES Other non-current liabilities consisted of the following: As of (In millions) June 30, December 31, Reclamation reserve $ 5.6 $ 5.4 Derivative instruments and hedges, fair value liabilities 3.7 5.5 Total $ 9.3 $ 10.9 A reconciliation of the Partnership’s reclamation reserve liability is as follows: For the period ended (In millions) June 30, December 31, Beginning reclamation reserve balance $ 5.4 $ 5.1 Accretion expense 0.2 0.3 Ending reclamation reserve balance $ 5.6 $ 5.4

REVENUE

REVENUE	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE The Partnership has one reportable segment and our revenue is derived from the sale of soda ash which is our sole and primary good and service. We account for revenue in accordance with Revenue from Contracts with Customers (“ASC 606”). Performance Obligations. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC 606. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. At contract inception, we assess the goods and services promised in contracts with customers and identify performance obligations for each promise to transfer to the customer, a good or service that is distinct. To identify the performance obligations, the Partnership considers all goods and services promised in the contract regardless of whether they are explicitly stated or are implied by customary business practices. From its analysis, the Partnership determined that the sale of soda ash is currently its only performance obligation. Many of our customer volume commitments are short-term and our performance obligations for the sale of soda ash are generally limited to single purchase orders. When performance obligations are satisfied. Substantially all of our revenue is recognized at a point-in-time when control of goods transfers to the customer. Transfer of Goods. The Partnership uses standard shipping terms across each customer contract with very few exceptions. Shipments to customers are made with terms stated as Free on Board (“FOB”) Shipping Point. Control typically transfers when goods are delivered to the carrier for shipment, which is the point at which the customer has the ability to direct the use of and obtain substantially all remaining benefits from the asset. Payment Terms. Our payment terms vary by the type and location of our customers. The term between invoicing and when payment is due is not significant and consistent with typical terms in the industry. Variable Consideration. We recognize revenue as the amount of consideration that we expect to receive in exchange for transferring promised goods or services to customers. We do not adjust the transaction price for the effects of a significant financing component, as the time period between control transfer of goods and services and expected payment is one year or less . At the time of sale, we estimate provisions for different forms of variable consideration (discounts, rebates, and pricing adjustments) based on historical experience, current conditions and contractual obligations, as applicable. The estimated transaction price is typically not subject to significant reversals. We adjust these estimates when the most likely amount of consideration we expect to receive changes, although these changes are typically immaterial. Returns, Refunds and Warranties. In the normal course of business, the Partnership does not accept returns, nor does it typically provide customers with the right to a refund. Freight. In accordance with ASC 606, the Partnership made a policy election to treat freight and related costs that occur after control of the related good transfers to the customer as fulfillment activities instead of separate performance obligations. Therefore freight is recognized at the point in which control of soda ash has transfered to the customer. Revenue Disaggregation . In accordance with ASC 606-10-50, the Partnership disaggregates revenue from contracts with customers into geographical regions. The Partnership determined that disaggregating revenue into these categories achieved the disclosure objectives to depict how the nature, timing, amount and uncertainty of revenue and cash flows are affected by economic factors. Refer to Note 12 , “Major Customers and Segment Reporting” for revenue disaggregated into geographical regions. Contract Balances . The timing of revenue recognition, billings and cash collections results in billed receivables, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities). Contract Assets. At the point of shipping, the Partnership has an unconditional right to payment that is only dependent on the passage of time. In general, customers are billed and a receivable is recorded as goods are shipped. These billed receivables are reported as “Accounts Receivable, net” on the Condensed Consolidated Balance Sheet as of June 30, 2019 . There were no contract assets as of June 30, 2019 or December 31, 2018 . Contract Liabilities. There may be situations where customers are required to prepay for freight and insurance prior to shipment. The Partnership has elected the practical expedient for its treatment of freight and therefore, such prepayments are considered a part of the single obligation to provide soda ash. In such instances, a contract liability for prepaid freight will be recorded. For the six months ended June 30, 2019 , there were no customers that required prepaid freight. There were no contract liabilities as of June 30, 2019 or December 31, 2018 . Practical Expedients Exceptions Incremental costs of obtaining contracts. We generally expense costs related to sales, including sales force salaries and marketing expenses, when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses. Unsatisfied performance obligations. We do not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less.

EMPLOYEE COMPENSATION

EMPLOYEE COMPENSATION	6 Months Ended
	Jun. 30, 2019
Retirement Benefits [Abstract]
EMPLOYEE COMPENSATION	EMPLOYEE COMPENSATION The Partnership participates in various benefit plans offered and administered by Ciner Corp and is allocated its portions of the annual costs related thereto. The specific plans are as follows: Retirement Plans - Benefits provided under the pension plan for salaried employees and pension plan for hourly employees (collectively, the “Retirement Plans”) are based upon years of service and average compensation for the highest 60 consecutive months of the employee’s last 120 months of service, as defined. Each Retirement Plan covers substantially all full-time employees hired before May 1, 2001. The Retirement Plans had a net unfunded liability balance of $55.7 million and $56.9 million at June 30, 2019 and December 31, 2018 , respectively. The current funding policy is to contribute an amount within the range of the minimum required and the maximum tax-deductible contribution. The Partnership’s allocated portion of the Retirement Plan’s net periodic pension costs for the three months ended June 30, 2019 and 2018 were $0.6 million and $0.1 million , respectively, and $0.8 million and $0.3 million for the six months ended June 30, 2019 and 2018 , respectively. Savings Plan - The 401(k) retirement plan (the “401(k) Plan”) covers all eligible hourly and salaried employees. Eligibility is limited to all domestic residents and any foreign expatriates who are in the United States indefinitely. The 401(k) Plan permits employees to contribute specified percentages of their compensation, while the Partnership makes contributions based upon specified percentages of employee contributions. Participants hired on or subsequent to May 1, 2001, will receive an additional contribution from the Partnership based on a percentage of the participant’s base pay. Contributions made to the 401(k) Plan for the three months ended June 30, 2019 and 2018 were $0.5 million , respectively, and $1.9 million and $1.8 million for the six months ended June 30, 2019 and 2018 , respectively. Postretirement Benefits - Most of the Partnership’s employees are eligible for postretirement benefits other than pensions if they reach retirement age while still employed. The postretirement benefits are accounted for by Ciner Corp on an accrual basis over an employee’s period of service. The postretirement plan, excluding pensions, are not funded, and Ciner Corp has the right to modify or terminate the plan. The post-retirement plan had a net unfunded liability of $8.0 million and $9.9 million at June 30, 2019 and December 31, 2018 , respectively. The decrease in the obligation as of June 30, 2019 as compared to December 31, 2018 is due to Ciner Corp amending its postretirement benefit plan during 2017 to increase eligibility requirements at which participants may begin receiving benefits, implementing a subsidy rather than a premium for the benefit plan, and eliminating plan eligibility for individuals hired after December 31, 2016. The result of these changes have resulted in a postretirement (benefit) cost being amortized to the liability recorded at Ciner Corp. The Partnership’s allocated portion of postretirement benefit for the three months ended June 30, 2019 and 2018 were benefits of $0.6 million and $0.7 million , respectively, and benefits of $1.2 million and $1.4 million for the six months ended June 30, 2019 and 2018 , respectively.

EQUITY - BASED COMPENSATION

EQUITY - BASED COMPENSATION	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
EQUITY - BASED COMPENSATION	EQUITY - BASED COMPENSATION We grant various types of equity-based awards to participants, including time restricted unit awards and total return restricted performance unit awards (“TR Performance Unit Awards”). The key terms of our restricted unit awards and TR Performance Unit Awards, including all financial disclosures, are set forth in our 2018 Annual Report. All employees, officers, consultants and non-employee directors of us and our parents and subsidiaries are eligible to be selected to participate in the Ciner Resource Partners LLC 2013 Long-Term Incentive Plan (as amended to date, the “Plan” or “LTIP”). As of June 30, 2019 , subject to further adjustment as provided in the Plan, a total of 0.7 million common units were available for awards under the Plan. Any common units tendered by a participant in payment of the tax liability with respect to an award, including common units withheld from any such award, will not be available for future awards under the Plan. Common units awarded under the Plan may be reserved or made available from our authorized and unissued common units or from common units reacquired (through open market transactions or otherwise). Any common units issued under the Plan through the assumption or substitution of outstanding grants from an acquired company will not reduce the number of common units available for awards under the Plan. If any common units subject to an award under the Plan are forfeited, those forfeited units will again be available for awards under the Plan. The Partnership has made a policy election to recognize forfeitures as they occur in lieu of estimating future forfeiture activity under the Plan. Non-employee Director Awards During the six months ended June 30, 2019 , a total of 8,832 common units were granted and fully vested to non-employee directors compared to 5,380 common units were granted during the six months ended June 30, 2018 . The grant date average fair value per unit of these awards was $25.48 and $27.89 for the six months ended June 30, 2019 and 2018 , respectively. The total fair value of these awards were approximately $0.2 million during each of the six months ended June 30, 2019 and 2018 . Time Restricted Unit Awards We grant restricted unit awards in the form of common units to certain employees which vest over a specified period of time, usually between one to three years, with vesting based on continued employment as of each applicable vesting date. Award recipients are entitled to distributions subject to the same restrictions as the underlying common unit. The awards are classified as equity awards, and are accounted for at fair value at grant date. The Partnership has made a policy election to recognize compensation expense attributable to restricted unit awards on a straight-line basis. The following table presents a summary of activity on the Time Restricted Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 71,436 $ 27.56 94,791 $ 27.22 Granted — — 37,914 26.13 Vested (32,087 ) 27.85 (42,892 ) 25.73 Forfeited — — (396 ) 28.46 Unvested at the end of the period 39,349 $ 27.33 89,417 $ 27.46 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units. Total Return Performance Unit Awards We grant TR Performance Unit Awards to certain employees. The TR Performance Unit Awards represent the right to receive a number of common units at a future date based on the achievement of market-based performance requirements in accordance with the TR Unit Performance Award agreement, and also include Distribution Equivalent Rights (“DERs”). DERs are the right to receive an amount equal to the accumulated cash distributions made during the period with respect to each common unit issued upon vesting. The TR Performance Unit Awards vest at the end of the performance period, usually between two to three years from the date of the grant. Performance is measured on the achievement of a specified level of total return, or TR, relative to the TR of a peer group comprised of other limited partnerships. The potential payout ranges from 0 - 200% of the grant target quantity and is adjusted based on our TR performance relative to the peer group. We utilized a Monte Carlo simulation model to estimate the grant date fair value of TR Performance Unit Awards granted to employees, adjusted for market conditions. This type of award requires the input of highly subjective assumptions, including expected volatility and expected distribution yield. Historical and implied volatilities were used in estimating the fair value of these awards. The following table presents a summary of activity on the TR Performance Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 52,974 $ 42.22 26,177 $ 42.93 Granted — — 33,994 41.52 Vested (2) (4,766 ) 43.93 — — Forfeited — — — — Unvested at the end of the period 48,208 $ 42.10 60,171 $ 42.14 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units. (2) Total vesting of 9,003 common units net of 5,457 of common units purchased by the Partnership in satisfaction of certain employee tax withholding obligations. Unrecognized Compensation Expense A summary of the Partnership’s unrecognized compensation expense for its unvested restricted time and performance based units, and the weighted-average periods over which the compensation expense is expected to be recognized are as following: Six Months Ended Six Months Ended Unrecognized Compensation Expense (In millions) Weighted Average to be Recognized (In years) Unrecognized Compensation Expense (In millions) Weighted Average to be Recognized (In years) Time-based units $ 0.8 1.18 $ 2.1 2.11 Performance-based units 0.8 1.36 1.9 2.25 Total $ 1.6 $ 4.0

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED OTHER COMPREHENSIVE LOSS Accumulated Other Comprehensive loss Accumulated other comprehensive loss, attributable to Ciner Resources, includes unrealized gains and losses on derivative financial instruments. Amounts recorded in accumulated other comprehensive loss as of June 30, 2019 and December 31, 2018 , and changes within the period, consisted of the following: (In millions) Gains and (Losses) on Cash Flow Hedges Balance at December 31, 2018 $ (3.8 ) Other comprehensive income before reclassification 0.5 Amounts reclassified from accumulated other comprehensive loss (0.3 ) Net current period other comprehensive income 0.2 Balance at June 30, 2019 $ (3.6 ) Other Comprehensive Loss Other comprehensive income/(loss), including the portion attributable to non-controlling interest, is derived from adjustments to reflect the unrealized gains/(loss) on derivative financial instruments. The components of other comprehensive income/(loss) consisted of the following: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Unrealized loss (gain) on derivatives: Mark to market adjustment on interest rate swap contracts $ (0.8 ) $ — $ (1.0 ) $ 0.1 Mark to market adjustment on natural gas forward contracts (0.8 ) (1.0 ) 1.4 (3.3 ) (Loss) gain on derivative financial instruments $ (1.6 ) $ (1.0 ) $ 0.4 $ (3.2 ) Reclassifications for the period The components of other comprehensive loss, attributable to Ciner Resources, that have been reclassified consisted of the following: Three Months Ended Six Months Ended Affected Line Items on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (In millions) 2019 2018 2019 2018 Details about other comprehensive loss components: Gains and losses on cash flow hedges: Interest rate swap contracts $ 0.1 $ — $ — $ — Interest expense Natural gas forward contracts 0.4 0.3 — 0.7 Cost of products sold Total reclassifications for the period $ 0.5 $ 0.3 $ — $ 0.7

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES From time to time we are party to various claims and legal proceedings related to our business. Although the outcome of these proceedings cannot be predicted with certainty, management does not currently expect any of the legal proceedings we are involved in to have a material effect on our business, financial condition and results of operations. We cannot predict the nature of any future claims or proceedings, nor the ultimate size or outcome of existing claims and legal proceedings and whether any damages resulting from them will be covered by insurance. Off-Balance Sheet Arrangements We have a self-bond agreement with the Wyoming Department of Environmental Quality under which we commit to pay directly for reclamation costs. The amount of the bond was $35.3 million and $32.9 million as of June 30, 2019 and December 31, 2018 , respectively, which is the amount we would need to pay the State of Wyoming for reclamation costs if we cease mining operations currently. The amount of this self-bond is subject to change upon periodic re-evaluation by the Land Quality Division. In May 2019, the State of Wyoming enacted legislation that limits our and other mine operator’s maximum amount of self-bonding. We have 18 months to comply with the new regulations, which, among other things would reduce the portion we are allowed to self-bond and will require us to seek other acceptable financial instruments to provide additional assurances for our reclamation obligations. While we cannot currently predict the availability, costs and terms of such additional financial instruments, as of the date of this Report we anticipate the impact of such additional financial instruments on our net income and liquidity will be limited.

AGREEMENTS AND TRANSACTIONS WIT

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES	6 Months Ended
	Jun. 30, 2019
Related Party Transactions [Abstract]
AGREEMENTS AND TRANSACTIONS WITH AFFILIATES	AGREEMENTS AND TRANSACTIONS WITH AFFILIATES Ciner Corp is the exclusive sales agent for the Partnership and through its membership in ANSAC, Ciner Corp is responsible for promoting and increasing the use and sale of soda ash and other refined or processed sodium products produced. ANSAC operates on a cooperative service-at-cost basis to its members such that typically any annual profit or loss is passed through to the members. In the event an ANSAC member exits or the ANSAC cooperative is dissolved, the exiting members are obligated for their respective portion of the residual net assets or deficit of the cooperative. On November 9, 2018, Ciner Corp delivered a notice to terminate its membership in ANSAC. The termination from ANSAC will be effective as of December 31, 2021. As of June 30, 2019 , we have not recognized an asset or liability related to its exit from ANSAC as such an amount is not currently probable or estimable. All actual sales and marketing costs incurred by Ciner Corp are charged directly to the Partnership. Selling, general and administrative expenses also include amounts charged to the Partnership by its affiliates principally consisting of salaries, benefits, office supplies, professional fees, travel, rent and other costs of certain assets used by the Partnership. On October 23, 2015, the Partnership entered into a Services Agreement (the “Services Agreement”), among the Partnership, our general partner and Ciner Corp. Pursuant to the Services Agreement, Ciner Corp has agreed to provide the Partnership with certain corporate, selling, marketing, and general and administrative services, in return for which the Partnership has agreed to pay Ciner Corp an annual management fee and reimburse Ciner Corp for certain third-party costs incurred in connection with providing such services. In addition, under the limited liability company agreement governing Ciner Wyoming, Ciner Wyoming reimburses us for employees who operate our assets and for support provided to Ciner Wyoming. These transactions do not necessarily represent arm's length transactions and may not represent all costs if Ciner Wyoming operated on a standalone basis. The total selling, general and administrative costs charged to the Partnership by affiliates were as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Ciner Corp $ 4.2 $ 3.6 $ 8.8 $ 7.7 ANSAC (1) 1.1 0.7 2.0 1.5 Total selling, general and administrative expenses - affiliates $ 5.3 $ 4.3 $ 10.8 $ 9.2 (1) ANSAC allocates its expenses to its members using a pro-rata calculation based on sales. Net sales to affiliates were as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 ANSAC $ 81.8 $ 49.6 $ 159.3 $ 115.5 Total $ 81.8 $ 49.6 $ 159.3 $ 115.5 The Partnership had accounts receivable from affiliates and due to affiliates as follows: As of June 30, December 31, June 30, December 31, (In millions) Accounts receivable from affiliates Due to affiliates ANSAC $ 64.7 $ 48.7 $ 1.1 $ 0.7 CIDT (1) 5.3 7.1 — — Ciner Corp 30.3 14.3 2.8 1.9 Total $ 100.3 $ 70.1 $ 3.9 $ 2.6 (1) “CIDT” refers to Ciner Ic ve Dis Ticaret Anonim Sirketi, an export affiliate of the Partnership.

MAJOR CUSTOMERS AND SEGMENT REP

MAJOR CUSTOMERS AND SEGMENT REPORTING	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
MAJOR CUSTOMERS AND SEGMENT REPORTING	MAJOR CUSTOMERS AND SEGMENT REPORTING Our operations are similar in geography, nature of products we provide, and type of customers we serve. As the Partnership earns substantially all of its revenues through the sale of soda ash mined at a single location, we have concluded that we have one operating segment for reporting purposes. The net sales by geographic area are as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Domestic $ 48.0 $ 60.3 $ 100.9 $ 115.6 International - ANSAC 81.8 49.6 159.3 115.5 Total net sales $ 129.8 $ 109.9 $ 260.2 $ 231.1

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The Partnership measures certain financial and non-financial assets and liabilities at fair value on a recurring basis. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. Fair value disclosures are reflected in a three-level hierarchy, maximizing the use of observable inputs and minimizing the use of unobservable inputs. A three-level valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability on the measurement date. The three levels are defined as follows: Ÿ Level 1-inputs to the valuation methodology are quoted prices (unadjusted) for an identical asset or liability in an active market. Ÿ Level 2-inputs to the valuation methodology include quoted prices for a similar asset or liability in an active market or model-derived valuations in which all significant inputs are observable for substantially the full term of the asset or liability. Ÿ Level 3-inputs to the valuation methodology are unobservable and significant to the fair value measurement of the asset or liability. Financial instruments consist primarily of cash and cash equivalents, accounts receivable, accounts payable and long-term debt. The carrying amounts of cash and cash equivalents, accounts receivable and accounts payable approximate their fair value because of the nature of such instruments. Our derivative financial instruments are measured at their fair value with Level 2 inputs based on quoted market values for similar but not identical financial instruments. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Derivative Financial Instruments We have interest rate swap contracts, designated as cash flow hedges, to mitigate our exposure to possible increases in interest rates. The swap contracts consist of four individual $12.5 million swaps with an aggregate notional value of $50.0 million at June 30, 2019 and December 31, 2018 . The swaps have various maturities through 2022. We enter into natural gas forward contracts, designated as cash flow hedges, to mitigate volatility in the price of natural gas related to a portion of the natural gas we consume. These contracts generally have various maturities through 2023 . These contracts had an aggregate notional value of $35.8 million and $41.2 million at June 30, 2019 and December 31, 2018 , respectively. The following table presents the fair value of derivative assets and liability derivatives and the respective locations on our unaudited condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 : Assets Liabilities Liabilities June 30, December 31, June 30, December 31, (In millions) Balance Sheet Location Fair Value Fair Value Balance Sheet Location Fair Value Fair Value Derivatives designated as hedges: Interest rate swap contracts - current $ — $ — Accrued Expenses $ 0.9 $ 0.3 Natural gas forward contracts - current Other current assets 0.1 — Accrued Expenses 2.9 1.6 Natural gas forward contracts - non-current Other non-current assets 0.3 — Other non-current liabilities 3.7 5.5 Total fair value of derivatives designated as hedging instruments $ 0.4 $ — $ 7.5 $ 7.4 Financial Assets and Liabilities not Measured at Fair Value The carrying value of our long-term debt materially reflects the fair value of our long-term debt as its key terms are similar to indebtedness with similar amounts, durations and credit risks. See Note 4 “Debt” for additional information on our debt arrangements.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Effective as of July 30, 2019 , the members of the Board of Managers of Ciner Wyoming LLC, approved a cash distribution to the members of Ciner Wyoming in the aggregate amount of $13.0 million . This distribution is payable on August 28, 2019 . On July 30, 2019 , the Partnership declared a cash distribution approved by the board of directors of its general partner. The cash distribution for the second quarter of 2019 of $0.340 per unit will be paid on August 28, 2019 to unitholders of record on August 9, 2019 .

CORPORATE STRUCTURE AND SUMMA_2

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations The unaudited condensed consolidated financial statements are composed of Ciner Resources LP (the “Partnership,” “CINR,” “Ciner Resources,” “we,” “us,” or “our”), a publicly traded Delaware limited partnership, and its consolidated subsidiary, Ciner Wyoming LLC (“Ciner Wyoming”), which is in the business of mining trona ore to produce soda ash. The Partnership’s operations consist solely of its investment in Ciner Wyoming. The Partnership was formed in April 2013 by Ciner Wyoming Holding Co. (“Ciner Holdings”), a wholly-owned subsidiary of Ciner Resources Corporation (“Ciner Corp”). Ciner Corp is a direct wholly-owned subsidiary of Ciner Enterprises Inc. (“Ciner Enterprises”), which is a direct wholly-owned subsidiary of WE Soda Ltd., a U.K. corporation (“WE Soda”). WE Soda is a direct wholly-owned subsidiary of KEW Soda Ltd., a U.K. corporation (“KEW Soda”), which is a direct wholly-owned subsidiary of Akkan Enerji ve Madencilik Anonim Şirketi (“Akkan”). Akkan is directly and wholly owned by Turgay Ciner, the Chairman of the Ciner Group (“Ciner Group”), a Turkish conglomerate of companies engaged in energy and mining (including soda ash mining), media and shipping markets. The Partnership owns a controlling interest comprised of 51.0% membership interest in Ciner Wyoming. All of our soda ash processed is currently sold to various domestic and international customers, including ANSAC which is an affiliate for export sales.
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applicable to interim period financial statements and reflect all adjustments, consisting of normal recurring accruals, which are necessary for fair presentation of the results of operations, financial position and cash flows for the periods presented. All intercompany transactions, balances, revenue and expenses have been eliminated in consolidation. The results of operations for the six months ended June 30, 2019 and 2018 are not necessarily indicative of the operating results for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes to audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 (the “ 2018 Annual Report”). As of January 1, 2019, we have adopted the guidance outlined in Accounting Standards Codification (“ASC”) Standard 842, Leases (“ASC 842”). For further information on the Partnership’s adoption of this standard, refer to “Recently Issued Accounting Pronouncements” below. There have been no other material changes in the significant accounting policies followed by us during the six month period ended June 30, 2019 from those disclosed in the 2018 Annual Report.
Use of Estimates	Use of Estimates The preparation of these unaudited condensed consolidated financial statements, in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the dates of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) to increase the transparency and comparability about leases among entities. Additional ASUs have been issued subsequent to ASU 2016-02 to provide supplementary clarification and implementation guidance for leases related to, among other things, the application of certain practical expedients, the rate implicit in the lease, lessee reassessment of lease classification, lessor reassessment of lease term and purchase options, variable payments that depend on an index or rate and certain transition adjustments. ASU 2016-02 and these additional ASUs are now codified as ASC 842. Pursuant to these updates, accounting for leases by lessors remains largely unchanged from current guidance. The update requires that lessees recognize a lease liability and a right of use asset for all leases (with the exception of short-term leases) at the commencement date of the lease and disclose key information about leasing arrangements. For leases less than 12 months, an entity is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The Partnership made this election upon adoption. In preparation for the new requirements, the Partnership completed its evaluation of the lease agreements during 2018. The Partnership adopted ASC 842 effective January 1, 2019 using a modified retrospective approach under which prior comparative periods will not be adjusted, as permitted by the guidance. The Partnership has determined that the adoption of the new standard did not have a material impact on the balance sheet or statement of operations because the Partnership has no material long term leases that are subject to ASC 842. Ciner Corp was determined to be the ultimate lessee for rail car lease agreements under ASC 842, and the Partnership will continue to incur an allocation of rent expense in relation to the use of rail cars leased by Ciner Corp. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (“ASU Topic 815”) – Targeted Improvements to Accounting for Hedging Activities. ASU Topic 815 aims to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, ASU Topic 815 makes certain targeted improvements to simplify the application of the existing hedge accounting guidance. ASU Topic 815 is effective for us beginning in the first quarter of 2019, with early application permitted. The Partnership adopted ASU Topic 815 effective January 1, 2019 and concluded there is no material impact to the Partnership’s consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, “Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force)” (“ASU 2018-15”), which amends ASC 350-40 to address a customer’s accounting for implementation costs incurred in a cloud computing arrangement (“CCA”) that is a service contract. ASU 2018-15 amends ASC 350 and clarifies that a customer should apply ASC 350-40 to determine which implementation costs should be capitalized in a CCA. The ASU does not expand on existing disclosure requirements except to require a description of the nature of hosting arrangements that are service contracts. Entities are permitted to apply either a retrospective or prospective transition approach to adopt the guidance. The Partnership is currently evaluating the potential impact this will have on the Partnership’s consolidated financial statements.

NET INCOME PER UNIT AND CASH _2

NET INCOME PER UNIT AND CASH DISTRIBUTION (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Calculation of Net Income Per Unit	The net income attributable to limited partner unitholders and the weighted average units for calculating basic and diluted net income per limited partner units were as follows: Three Months Ended Six Months Ended (In millions, except per unit data) 2019 2018 2019 2018 Numerator: Net income attributable to Ciner Resources LP $ 11.3 $ 16.8 $ 23.6 $ 26.9 Less: General partner’s interest in net income 0.3 0.3 0.5 0.5 Total limited partners’ interest in net income $ 11.0 $ 16.5 $ 23.1 $ 26.4 Denominator: Weighted average limited parter units outstanding: Weighted average common units outstanding (basic and diluted) 19.7 19.7 19.7 19.7 Net income per limited partner units: Net income per limited partner units (basic and diluted) $ 0.56 $ 0.83 $ 1.17 $ 1.34
Calculation of Limited Partners' Interest in Net Income	The calculation of limited partners’ interest in net income is as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Net income attributable to common unitholders: Distributions (1) $ 6.7 $ 11.2 $ 13.4 $ 22.3 Undistributed earnings (Distributions in excess) of net income 4.3 5.3 9.7 4.1 Common unitholders’ interest in net income $ 11.0 $ 16.5 $ 23.1 $ 26.4 (1) Distributions declared per common unit for the period $ 0.340 $ 0.567 $ 0.680 $ 1.134
Percentage Allocations of Distributions From Operating Surplus	The following table illustrates the percentage allocations of distributions from operating surplus between the unitholders and our general partner based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of our general partner and the unitholders in any distributions from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution per Unit Target Amount.” The percentage interests shown for our unitholders and our general partner for the minimum quarterly distribution also apply to quarterly distribution amounts that are less than the minimum quarterly distribution, including for the declared quarterly distributions of $0.340 per unit for the second quarter of 2019. Other than the requirement in our partnership agreement to distribute all of our available cash (as defined there) each quarter, the partnership agreement of the Partnership does not contain a requirement for the Partnership to pay any quarterly cash distributions to its unitholders, and our general partner has considerable discretion to establish cash reserves that would reduce the amount of available cash we distribute to unit holders. The Partnership does not guarantee that it will pay the target amount of the minimum quarterly distribution listed below (or any distributions) on its units in any quarter. The percentage interests set forth below for our general partner (1) include its 2.0% general partner interest, (2) assume that our general partner has contributed any additional capital necessary to maintain its 2.0% general partner interest, (3) assume that our general partner has not transferred its IDRs and (4) assume there are no arrearages on common units. Marginal Percentage Interest in Distributions Total Quarterly Distribution per Unit Target Amount Unitholders General Partner Minimum Quarterly Distribution $0.5000 98.0 % 2.0 % First Target Distribution above $0.5000 up to $0.5750 98.0 % 2.0 % Second Target Distribution above $0.5750 up to $0.6250 85.0 % 15.0 % Third Target Distribution above $0.6250 up to $0.7500 75.0 % 25.0 % Thereafter above $0.7500 50.0 % 50.0 %

INVENTORY (Tables)

INVENTORY (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following: As of (In millions) June 30, December 31, Raw materials $ 10.7 $ 10.9 Finished goods 6.0 5.1 Stores inventory 5.7 6.3 Total $ 22.4 $ 22.3

DEBT (Tables)

DEBT (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Components of Long-term Debt	Long-term debt consisted of the following: As of (In millions) June 30, December 31, Ciner Wyoming Credit Facility, unsecured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 3.91% and 3.99% at June 30, 2019 and December 31, 2018, respectively $ 145.5 $ 99.0 Total debt 145.5 99.0 Current portion of long-term debt — — Total long-term debt $ 145.5 $ 99.0
Aggregate Maturities on Long-term Debt	Aggregate maturities required on long-term debt at June 30, 2019 are due in future years as follows: (In millions) Amount 2021 $ — 2022 145.5 2023 to 2025 and beyond — Total $ 145.5

OTHER NON-CURRENT LIABILITIES (

OTHER NON-CURRENT LIABILITIES (Tables)	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Other Non-current Liabilities	Other non-current liabilities consisted of the following: As of (In millions) June 30, December 31, Reclamation reserve $ 5.6 $ 5.4 Derivative instruments and hedges, fair value liabilities 3.7 5.5 Total $ 9.3 $ 10.9
Reconciliation of Partnership's Reclamation Reserve Liability	A reconciliation of the Partnership’s reclamation reserve liability is as follows: For the period ended (In millions) June 30, December 31, Beginning reclamation reserve balance $ 5.4 $ 5.1 Accretion expense 0.2 0.3 Ending reclamation reserve balance $ 5.6 $ 5.4

EQUITY - BASED COMPENSATION (Ta

EQUITY - BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Time Restricted Unit Award Activity	The following table presents a summary of activity on the Time Restricted Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 71,436 $ 27.56 94,791 $ 27.22 Granted — — 37,914 26.13 Vested (32,087 ) 27.85 (42,892 ) 25.73 Forfeited — — (396 ) 28.46 Unvested at the end of the period 39,349 $ 27.33 89,417 $ 27.46 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units.
Schedule of Time Restricted Performance Unit Award Activity	The following table presents a summary of activity on the TR Performance Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 52,974 $ 42.22 26,177 $ 42.93 Granted — — 33,994 41.52 Vested (2) (4,766 ) 43.93 — — Forfeited — — — — Unvested at the end of the period 48,208 $ 42.10 60,171 $ 42.14 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units. (2) Total vesting of 9,003 common units net of 5,457 of common units purchased by the Partnership in satisfaction of certain employee tax withholding obligations.
Schedule of Unrecognized Compensation Expense for Unvested Awards	A summary of the Partnership’s unrecognized compensation expense for its unvested restricted time and performance based units, and the weighted-average periods over which the compensation expense is expected to be recognized are as following: Six Months Ended Six Months Ended Unrecognized Compensation Expense (In millions) Weighted Average to be Recognized (In years) Unrecognized Compensation Expense (In millions) Weighted Average to be Recognized (In years) Time-based units $ 0.8 1.18 $ 2.1 2.11 Performance-based units 0.8 1.36 1.9 2.25 Total $ 1.6 $ 4.0

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	Amounts recorded in accumulated other comprehensive loss as of June 30, 2019 and December 31, 2018 , and changes within the period, consisted of the following: (In millions) Gains and (Losses) on Cash Flow Hedges Balance at December 31, 2018 $ (3.8 ) Other comprehensive income before reclassification 0.5 Amounts reclassified from accumulated other comprehensive loss (0.3 ) Net current period other comprehensive income 0.2 Balance at June 30, 2019 $ (3.6 )
Components of Other Comprehensive Income/(Loss)	The components of other comprehensive income/(loss) consisted of the following: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Unrealized loss (gain) on derivatives: Mark to market adjustment on interest rate swap contracts $ (0.8 ) $ — $ (1.0 ) $ 0.1 Mark to market adjustment on natural gas forward contracts (0.8 ) (1.0 ) 1.4 (3.3 ) (Loss) gain on derivative financial instruments $ (1.6 ) $ (1.0 ) $ 0.4 $ (3.2 )
Schedule of Reclassifications Out of Other Comprehensive Loss, Attributable to Ciner Resources	The components of other comprehensive loss, attributable to Ciner Resources, that have been reclassified consisted of the following: Three Months Ended Six Months Ended Affected Line Items on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (In millions) 2019 2018 2019 2018 Details about other comprehensive loss components: Gains and losses on cash flow hedges: Interest rate swap contracts $ 0.1 $ — $ — $ — Interest expense Natural gas forward contracts 0.4 0.3 — 0.7 Cost of products sold Total reclassifications for the period $ 0.5 $ 0.3 $ — $ 0.7

AGREEMENTS AND TRANSACTIONS W_2

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES (Tables)	6 Months Ended
	Jun. 30, 2019
Costs Charged by Affiliates
Related Party Transaction [Line Items]
Schedule of Transactions with Affiliates	The total selling, general and administrative costs charged to the Partnership by affiliates were as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Ciner Corp $ 4.2 $ 3.6 $ 8.8 $ 7.7 ANSAC (1) 1.1 0.7 2.0 1.5 Total selling, general and administrative expenses - affiliates $ 5.3 $ 4.3 $ 10.8 $ 9.2 (1) ANSAC allocates its expenses to its members using a pro-rata calculation based on sales.
Net Sales to Affiliates
Related Party Transaction [Line Items]
Schedule of Transactions with Affiliates	Net sales to affiliates were as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 ANSAC $ 81.8 $ 49.6 $ 159.3 $ 115.5 Total $ 81.8 $ 49.6 $ 159.3 $ 115.5
Receivables and Payables with Affiliates
Related Party Transaction [Line Items]
Schedule of Transactions with Affiliates	The Partnership had accounts receivable from affiliates and due to affiliates as follows: As of June 30, December 31, June 30, December 31, (In millions) Accounts receivable from affiliates Due to affiliates ANSAC $ 64.7 $ 48.7 $ 1.1 $ 0.7 CIDT (1) 5.3 7.1 — — Ciner Corp 30.3 14.3 2.8 1.9 Total $ 100.3 $ 70.1 $ 3.9 $ 2.6 (1) “CIDT” refers to Ciner Ic ve Dis Ticaret Anonim Sirketi, an export affiliate of the Partnership.

MAJOR CUSTOMERS AND SEGMENT R_2

MAJOR CUSTOMERS AND SEGMENT REPORTING (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Schedule of Net Sales By Geographic Area	The net sales by geographic area are as follows: Three Months Ended Six Months Ended (In millions) 2019 2018 2019 2018 Domestic $ 48.0 $ 60.3 $ 100.9 $ 115.6 International - ANSAC 81.8 49.6 159.3 115.5 Total net sales $ 129.8 $ 109.9 $ 260.2 $ 231.1

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Derivative Assets and Liabilities	The following table presents the fair value of derivative assets and liability derivatives and the respective locations on our unaudited condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 : Assets Liabilities Liabilities June 30, December 31, June 30, December 31, (In millions) Balance Sheet Location Fair Value Fair Value Balance Sheet Location Fair Value Fair Value Derivatives designated as hedges: Interest rate swap contracts - current $ — $ — Accrued Expenses $ 0.9 $ 0.3 Natural gas forward contracts - current Other current assets 0.1 — Accrued Expenses 2.9 1.6 Natural gas forward contracts - non-current Other non-current assets 0.3 — Other non-current liabilities 3.7 5.5 Total fair value of derivatives designated as hedging instruments $ 0.4 $ — $ 7.5 $ 7.4

CORPORATE STRUCTURE AND SUMMA_3

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Ciner Wyoming	Jun. 30, 2019
Noncontrolling Interest [Line Items]
Membership interest	51.00%
Membership interest attributable to noncontrolling interest	49.00%

NET INCOME PER UNIT AND CASH _3

NET INCOME PER UNIT AND CASH DISTRIBUTION - Calculation of net income per unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income attributable to Ciner Resources LP	$ 11.3	$ 16.8	$ 23.6	$ 26.9
Less: General partner’s interest in net income	0.3	0.3	0.5	0.5
Total limited partners’ interest in net income	$ 11	$ 16.5	$ 23.1	$ 26.4
Weighted average limited parter units outstanding:
Weighted average common units outstanding (basic and diluted) (shares)	19.7	19.7	19.7	19.7
Net income per limited partner units:
Net income per limited partner units (basic and diluted) (dollars per share)	$ 0.56	$ 0.83	$ 1.17	$ 1.34
Distributions	$ 6.7	$ 11.2	$ 13.4	$ 22.3
Undistributed earnings (Distributions in excess) of net income	4.3	5.3	9.7	4.1
Total limited partners’ interest in net income	$ 11	$ 16.5	$ 23.1	$ 26.4
Distributions declared per common unit for the period (dollars per share)	$ 0.340	$ 0.5670	$ 0.680	$ 1.134

NET INCOME PER UNIT AND CASH _4

NET INCOME PER UNIT AND CASH DISTRIBUTION - Narrative (Details) T in Millions	Jul. 30, 2019$ / shares	Jun. 30, 2019T$ / shares	Jun. 30, 2018$ / shares	Jun. 30, 2019T$ / shares	Jun. 30, 2018$ / shares
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Distributions declared per common unit for the period (dollars per share)		$ 0.340	$ 0.5670	$ 0.680	$ 1.134
Number of soda ash per year (in tons) | T		3.5		3.5
Percentage limit to keep cash distributions lowered				50.00%
General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Percentage of general partner ownership interest held				2.00%
Second Target Distribution | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus				13.00%
Third Target Distribution | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus				23.00%
Thereafter | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus				48.00%
Subsequent Event
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Distributions declared per common unit for the period (dollars per share)	$ 0.34000
Minimum
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Term of funding for project				27 months
Maximum
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Term of funding for project				33 months

NET INCOME PER UNIT AND CASH _5

NET INCOME PER UNIT AND CASH DISTRIBUTION - Target distributions and marginal percentage interests (Details)	6 Months Ended
	Jun. 30, 2019$ / shares
Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (dollars per share)	$ 0.5000
First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (dollars per share)	0.5000
Maximum quarterly distribution target levels (dollars per share)	0.5750
Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (dollars per share)	0.5750
Maximum quarterly distribution target levels (dollars per share)	0.6250
Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (dollars per share)	0.6250
Maximum quarterly distribution target levels (dollars per share)	0.7500
Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (dollars per share)	$ 0.7500
Unitholders | Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	98.00%
Unitholders | First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	98.00%
Unitholders | Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	85.00%
Unitholders | Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	75.00%
Unitholders | Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	50.00%
General Partner | Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	2.00%
General Partner | First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	2.00%
General Partner | Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	15.00%
General Partner | Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	25.00%
General Partner | Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	50.00%

INVENTORY (Details)

INVENTORY (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 10.7	$ 10.9
Finished goods	6	5.1
Stores inventory	5.7	6.3
Total	$ 22.4	$ 22.3

DEBT - Components of long-term

DEBT - Components of long-term debt (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt
Total debt	$ 145.5	$ 99
Current portion of long-term debt	0	0
Total long-term debt	$ 145.5	$ 99
Ciner Wyoming Credit Facility | Line of Credit | Revolving credit facility
Debt
Interest rate (as a percent)	3.91%	3.99%
Total debt	$ 145.5	$ 99

DEBT - Maturities of long-term

DEBT - Maturities of long-term debt (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2021	$ 0
2022	145.5
2023 to 2025 and beyond	0
Total debt	$ 145.5	$ 99

OTHER NON-CURRENT LIABILITIES_2

OTHER NON-CURRENT LIABILITIES (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Reclamation reserve	$ 5.4	$ 5.1	$ 5.6	$ 5.4
Derivative instruments and hedges, fair value liabilities			3.7	5.5
Total			$ 9.3	$ 10.9
Reclamation reserve
Beginning reclamation reserve balance	5.4	5.1
Accretion expense	0.2	0.3
Ending reclamation reserve balance	$ 5.6	$ 5.4

REVENUE (Details)

REVENUE (Details)	6 Months Ended
	Jun. 30, 2019USD ($)segment	Dec. 31, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Number of operating segments | segment	1
Contract assets	$ 0	$ 0
Contract liabilities	$ 0	$ 0

EMPLOYEE COMPENSATION (Details)

EMPLOYEE COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Average compensation period			60 months
Period of last service			120 months
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net unfunded liability	$ 55.7		$ 55.7		$ 56.9
Net periodic pension cost (credit)	0.6	$ 0.1	0.8	$ 0.3
Savings Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions made by employer	0.5	0.5	1.9	1.8
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net unfunded liability	8		8		$ 9.9
Net periodic pension cost (credit)	$ (0.6)	$ (0.7)	$ (1.2)	$ (1.4)

EQUITY - BASED COMPENSATION - N

EQUITY - BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common units available under plan (shares)	700,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common units granted (shares)	0	37,914
Common units grant date average fair value (dollars per share)	$ 27.85	$ 25.73
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
TR Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common units granted (shares)	0	33,994
Common units grant date average fair value (dollars per share)	$ 43.93	$ 0
TR Performance Unit Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	2 years
Payout range	0.00%
TR Performance Unit Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Payout range	200.00%
Director - non employee | Common units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common units granted and fully vested (shares)	8,832
Number of common units granted (shares)		5,380
Common units grant date average fair value (dollars per share)	$ 25.48	$ 27.89
Fair value of common units granted and vested	$ 0.2	$ 0.2

EQUITY - BASED COMPENSATION - S

EQUITY - BASED COMPENSATION - Schedule of Restricted Unit Award Activity (Details) - Restricted Stock Units (RSUs) - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Number of Common Units
Unvested at the beginning of period (shares)	71,436	94,791
Granted (shares)	0	37,914
Vested (shares)	(32,087)	(42,892)
Forfeited (shares)	0	(396)
Unvested at the end of the period (shares)	39,349	89,417
Grant-Date Average Fair Value per Unit
Unvested at the beginning of period (dollars per share)	$ 27.56	$ 27.22
Granted (dollars per share)	0	26.13
Vested (dollars per share)	27.85	25.73
Forfeited (dollars per share)	0	28.46
Unvested at the end of the period (dollars per share)	$ 27.33	$ 27.46

EQUITY - BASED COMPENSATION -_2

EQUITY - BASED COMPENSATION - Schedule of Total Return Performance Unit Award Activity (Details) - TR Performance Unit Awards - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Number of Common Units
Unvested at the beginning of period (shares)	52,974	26,177
Granted (shares)	0	33,994
Vested (shares)	(4,766)	0
Forfeited (shares)	0	0
Unvested at the end of the period (shares)	48,208	60,171
Grant-Date Average Fair Value per Unit
Unvested at the beginning of period (dollars per share)	$ 42.22	$ 42.93
Granted (dollars per share)	0	41.52
Vested (dollars per share)	43.93	0
Forfeited (dollars per share)	0	0
Unvested at the end of the period (dollars per share)	$ 42.10	$ 42.14
Vested, gross of tax withholdings (shares)	9,003
Common units purchased by Partnership in satisfaction of certain employee tax withholding obligations (in shares)	5,457

EQUITY - BASED COMPENSATION - U

EQUITY - BASED COMPENSATION - Unrecognized Compensation Expense (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 1.6	$ 4
Time-Based Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0.8	$ 2.1
Weighted average to be recognized (in years)	1 year 2 months 4 days	2 years 1 month 10 days
Performance-Based Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0.8	$ 1.9
Weighted average to be recognized (in years)	1 year 4 months 10 days	2 years 2 months 30 days

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive loss (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 265.9	$ 260.1	$ 243.2	$ 248.2	$ 260.1	$ 248.2
Net current period other comprehensive income	(1.6)	2	(1)	(2.2)
Ending balance	272.6	265.9	$ 253.6	$ 243.2	272.6	$ 253.6
Gains and (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ (3.8)			(3.8)
Other comprehensive income before reclassification					0.5
Amounts reclassified from accumulated other comprehensive loss					(0.3)
Net current period other comprehensive income					0.2
Ending balance	$ (3.6)				$ (3.6)

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE LOSS - Components of Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	$ (1.6)		$ 0.4
Unrealized loss (gain) on derivative financial instruments		$ (1)		$ (3.2)
Interest Rate Swap Contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	(0.8)		(1)
Unrealized loss (gain) on derivative financial instruments		0		0.1
Natural Gas Forward Contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	$ (0.8)		$ 1.4
Unrealized loss (gain) on derivative financial instruments		$ (1)		$ (3.3)

ACCUMULATED OTHER COMPREHENSI_5

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Reclassifications out of Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	$ 1.6	$ 1.2	$ 3	$ 2.5
Cost of products sold	90.6	88.7	180.8	175.1
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total reclassifications for the period	0.5	0.3	0	0.7
Gains and (Losses) on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total reclassifications for the period			0.3
Gains and (Losses) on Cash Flow Hedges | Interest Rate Swap Contracts | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	0.1	0	0	0
Gains and (Losses) on Cash Flow Hedges | Natural Gas Forward Contracts | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of products sold	$ 0.4	$ 0.3	$ 0	$ 0.7

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Self-bond agreement for reclamation costs
Other Commitments [Line Items]
Off balance sheet commitment	$ 35.3	$ 32.9

AGREEMENTS AND TRANSACTIONS W_3

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Costs charged by affiliates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates	$ 5.3	$ 4.3	$ 10.8	$ 9.2
Ciner Corp
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates	4.2	3.6	8.8	7.7
ANSAC
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates	$ 1.1	$ 0.7	$ 2	$ 1.5

AGREEMENTS AND TRANSACTIONS W_4

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Net sales to affiliates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Related Party Transaction [Line Items]
Net sales to affiliates	$ 81.8	$ 49.6	$ 159.3	$ 115.5
ANSAC
Related Party Transaction [Line Items]
Net sales to affiliates	$ 81.8	$ 49.6	$ 159.3	$ 115.5

AGREEMENTS AND TRANSACTIONS W_5

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Receivables from or payables to affiliates (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Accounts receivable from affiliates	$ 100.3	$ 70.1
Due to affiliates	3.9	2.6
ANSAC
Related Party Transaction [Line Items]
Accounts receivable from affiliates	64.7	48.7
Due to affiliates	1.1	0.7
CIDT
Related Party Transaction [Line Items]
Accounts receivable from affiliates	5.3	7.1
Due to affiliates	0	0
Ciner Corp
Related Party Transaction [Line Items]
Accounts receivable from affiliates	30.3	14.3
Due to affiliates	$ 2.8	$ 1.9

MAJOR CUSTOMERS AND SEGMENT R_3

MAJOR CUSTOMERS AND SEGMENT REPORTING - Narrative (Details)	6 Months Ended
	Jun. 30, 2019segment
Segment Reporting [Abstract]
Number of operating segments	1

MAJOR CUSTOMERS AND SEGMENT R_4

MAJOR CUSTOMERS AND SEGMENT REPORTING - Sales by geographic area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Sales by geographical area
Revenue by major product line	$ 129.8	$ 109.9	$ 260.2	$ 231.1
Domestic
Sales by geographical area
Revenue by major product line	48	60.3	100.9	115.6
International | ANSAC
Sales by geographical area
Revenue by major product line	$ 81.8	$ 49.6	$ 159.3	$ 115.5

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details)	Jun. 30, 2019USD ($)swap	Dec. 31, 2018USD ($)
Interest Rate Swap Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of swap contracts | swap	4
Natural Gas Forward Contracts | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative aggregate notional value	$ 35,800,000	$ 41,200,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap Contracts | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	12,500,000
Derivative aggregate notional value	$ 50,000,000

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Fair Value of Derivative Assets and Liability (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of derivatives designated as hedging instruments	$ 0.4	$ 0
Total fair value of derivatives designated as hedging instruments	7.5	7.4
Other current assets | Interest Rate Swap Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, current	0	0
Other current assets | Natural Gas Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, current	0.1	0
Other non-current assets | Natural Gas Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivativeasset, noncurrent	0.3	0
Accrued Expenses | Interest Rate Swap Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, current	0.9	0.3
Accrued Expenses | Natural Gas Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, current	2.9	1.6
Other non-current liabilities | Natural Gas Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, noncurrent	$ 3.7	$ 5.5

SUBSEQUENT EVENTS - Narrative (

SUBSEQUENT EVENTS - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Subsequent Event [Line Items]
Distributions declared per common unit for the period (dollars per share)		$ 0.340	$ 0.5670	$ 0.680	$ 1.134
Subsequent Event
Subsequent Event [Line Items]
Cash distribution approved	$ 13
Distributions declared per common unit for the period (dollars per share)	$ 0.34000