Martin Midstream Partners (MMLP) 10-Q 25 Jul 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 25, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	MARTIN MIDSTREAM PARTNERS LP
Entity Central Index Key	1,176,334
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		39,052,237

CONSOLIDATED AND CONDENSED BALA

CONSOLIDATED AND CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets
Cash	$ 610	$ 27
Accounts and other receivables, less allowance for doubtful accounts of $405 and $314, respectively	60,884	107,242
Product exchange receivables	174	29
Inventories (Note 6)	113,100	97,252
Due from affiliates	21,031	23,668
Other current assets	5,368	4,866
Assets held for sale (Note 4)	8,158	9,579
Total current assets	209,325	242,663
Property, plant and equipment, at cost	1,273,392	1,253,065
Accumulated depreciation	(450,564)	(421,137)
Property, plant and equipment, net	822,828	831,928
Goodwill	17,296	17,296
Investment in WTLPG (Note 7)	141,114	128,810
Other assets, net (Note 9)	28,202	32,801
Total assets	1,218,765	1,253,498
Liabilities and Partners’ Capital
Trade and other accounts payable	72,945	92,567
Product exchange payables	13,015	11,751
Due to affiliates	1,271	3,168
Income taxes payable	400	510
Fair value of derivatives (Note 10)	572	72
Other accrued liabilities (Note 9)	23,093	26,340
Total current liabilities	111,296	134,408
Long-term debt, net (Note 8)	831,928	812,632
Other long-term obligations	10,842	8,217
Total liabilities	954,066	955,257
Commitments and contingencies (Note 15)
Partners’ capital (Note 11)	264,699	298,241
Total partners’ capital	264,699	298,241
Total liabilities and partners' capital	$ 1,218,765	$ 1,253,498

CONSOLIDATED AND CONDENSED BAL3

CONSOLIDATED AND CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 405	$ 314

CONSOLIDATED AND CONDENSED STAT

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenues		$ 216,571	$ 193,922	$ 500,775	$ 447,247
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		149,587	121,302	349,400	282,093
Expenses:
Operating expenses	[1]	31,510	32,552	62,964	65,926
Selling, general and administrative	[1]	8,572	8,909	18,240	18,830
Depreciation and amortization		20,891	20,326	40,101	45,662
Total costs and expenses		210,560	183,089	470,705	412,511
Other operating income (loss)		(490)	15	(492)	(140)
Operating income		5,521	10,848	29,578	34,596
Other income (expense):
Equity in earnings of WTLPG		1,131	853	2,726	1,758
Interest expense, net		(13,766)	(11,219)	(26,451)	(22,139)
Other, net		0	520	0	550
Total other expense		(12,635)	(9,846)	(23,725)	(19,831)
Net income (loss) before taxes		(7,114)	1,002	5,853	14,765
Income tax expense		(132)	(13)	(281)	(193)
Net income (loss)		(7,246)	989	5,572	14,572
Less general partner's interest in net (income) loss		145	(19)	(111)	(291)
Less (income) loss allocable to unvested restricted units		6	(3)	(2)	(38)
Limited partners' interest in net income (loss)		$ (7,095)	$ 967	$ 5,459	$ 14,243
Net income (loss) per unit attributable to limited partners - basic (USD per share)		$ (0.18)	$ 0.03	$ 0.14	$ 0.38
Net income (loss) per unit attributable to limited partners - diluted (USD per share)		$ (0.18)	$ 0.03	$ 0.14	$ 0.38
Weighted average limited partner units - basic (in shares)		38,722,037	38,357,293	38,828,845	37,842,140
Weighted average limited partner units - diluted (in shares)		38,722,037	38,413,911	38,834,421	37,894,616
Terminalling and storage
Revenues:
Revenues	[1]	$ 24,090	$ 24,695	$ 48,154	$ 49,353
Marine transportation
Revenues:
Revenues	[1]	12,739	12,433	24,193	25,254
Natural gas services
Revenues:
Revenues	[1]	13,804	14,838	29,160	29,503
Sulfur services
Revenues:
Revenues		2,787	2,850	5,574	5,700
Product sales
Revenues:
Revenues	[1]	163,151	139,106	393,694	337,437
Natural gas services
Revenues:
Revenues	[1]	90,643	73,666	249,806	200,323
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	87,642	70,198	230,599	178,377
Sulfur services
Revenues:
Revenues	[1]	35,684	32,027	70,584	71,554
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	28,739	21,207	52,635	45,690
Terminalling and storage
Revenues:
Revenues	[1]	36,824	33,413	73,304	65,560
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	$ 33,206	$ 29,897	$ 66,166	$ 58,026
[1]	Related Party Transactions Included Above Three Months Ended Six Months Ended June 30, June 30, 2018 2017 2018 2017 Revenues:* Terminalling and storage $ 20,507 $ 20,331 $ 40,532 $ 40,035 Marine transportation 4,105 4,187 7,718 8,512 Natural gas services — 6 — 118 Product Sales 426 724 1,068 2,154 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Natural gas services 3,099 2,909 7,417 11,803 Sulfur services 4,345 3,767 8,871 7,442 Terminalling and storage 8,009 4,119 14,567 9,186 Expenses: Operating expenses 14,339 16,452 27,723 32,828 Selling, general and administrative 6,498 6,500 14,219 14,068

CONSOLIDATED AND CONDENSED STA5

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - Related Party Transactions - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenues		$ 216,571	$ 193,922	$ 500,775	$ 447,247
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		149,587	121,302	349,400	282,093
Expenses:
Operating expenses	[1]	31,510	32,552	62,964	65,926
Selling, general and administrative	[1]	8,572	8,909	18,240	18,830
Terminalling and storage
Revenues:
Revenues	[1]	24,090	24,695	48,154	49,353
Marine transportation
Revenues:
Revenues	[1]	12,739	12,433	24,193	25,254
Natural gas services
Revenues:
Revenues	[1]	13,804	14,838	29,160	29,503
Product Sales
Revenues:
Revenues	[1]	163,151	139,106	393,694	337,437
Natural gas services
Revenues:
Revenues	[1]	90,643	73,666	249,806	200,323
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	87,642	70,198	230,599	178,377
Sulfur services
Revenues:
Revenues	[1]	35,684	32,027	70,584	71,554
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	28,739	21,207	52,635	45,690
Terminalling and storage
Revenues:
Revenues	[1]	36,824	33,413	73,304	65,560
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	33,206	29,897	66,166	58,026
Related Party
Expenses:
Operating expenses		14,339	16,452	27,723	32,828
Selling, general and administrative		6,498	6,500	14,219	14,068
Related Party | Terminalling and storage
Revenues:
Revenues		20,507	20,331	40,532	40,035
Related Party | Marine transportation
Revenues:
Revenues		4,105	4,187	7,718	8,512
Related Party | Natural gas services
Revenues:
Revenues		0	6	0	118
Related Party | Product Sales
Revenues:
Revenues		426	724	1,068	2,154
Related Party | Natural gas services
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		3,099	2,909	7,417	11,803
Related Party | Sulfur services
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		4,345	3,767	8,871	7,442
Related Party | Terminalling and storage
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		$ 8,009	$ 4,119	$ 14,567	$ 9,186
[1]	Related Party Transactions Included Above Three Months Ended Six Months Ended June 30, June 30, 2018 2017 2018 2017 Revenues:* Terminalling and storage $ 20,507 $ 20,331 $ 40,532 $ 40,035 Marine transportation 4,105 4,187 7,718 8,512 Natural gas services — 6 — 118 Product Sales 426 724 1,068 2,154 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Natural gas services 3,099 2,909 7,417 11,803 Sulfur services 4,345 3,767 8,871 7,442 Terminalling and storage 8,009 4,119 14,567 9,186 Expenses: Operating expenses 14,339 16,452 27,723 32,828 Selling, general and administrative 6,498 6,500 14,219 14,068

CONSOLIDATED AND CONDENSED STA6

CONSOLIDATED AND CONDENSED STATEMENTS OF CAPITAL - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance			$ 298,241	$ 312,006
Net income	$ (7,246)	$ 989	5,572	14,572
Issuance of common units, net			(118)	51,071
Issuance of restricted units			0	0
Forfeiture of restricted units			0	0
General partner contribution				1,098
Cash distributions			(39,217)	(37,706)
Unit-based compensation			520	405
Purchase of treasury units			(273)	(4)
Excess purchase price over carrying value of acquired assets			(26)	(7,887)
Reimbursement of excess purchase price over carrying value of acquired assets				1,125
Ending balance	$ 264,699	$ 334,680	$ 264,699	$ 334,680
Common Limited
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)			38,444,612	35,452,062
Beginning balance			$ 290,927	$ 304,594
Net income			$ 5,461	$ 14,281
Issuance of common units, net (in shares)			0	2,990,000
Issuance of common units, net			$ (118)	$ 51,071
Issuance of restricted units (in shares)			633,425	12,000
Issuance of restricted units			$ 0	$ 0
Forfeiture of restricted units (in shares)			(7,000)	(1,750)
Forfeiture of restricted units			$ 0	$ 0
Cash distributions			(38,433)	(36,952)
Unit-based compensation			$ 520	$ 405
Purchase of treasury units (in shares)			(18,800)	(200)
Purchase of treasury units			$ (273)	$ (4)
Excess purchase price over carrying value of acquired assets			$ (26)	(7,887)
Reimbursement of excess purchase price over carrying value of acquired assets				$ 1,125
Ending balance (in shares)	39,052,237	38,452,112	39,052,237	38,452,112
Ending balance	$ 258,058	$ 326,633	$ 258,058	$ 326,633
General Partner Amount
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance			7,314	7,412
Net income			111	291
General partner contribution				1,098
Cash distributions			(784)	(754)
Ending balance	$ 6,641	$ 8,047	$ 6,641	$ 8,047

CONSOLIDATED AND CONDENSED STA7

CONSOLIDATED AND CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 5,572	$ 14,572
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,101	45,662
Amortization of deferred debt issuance costs	1,689	1,445
Amortization of premium on notes payable	(153)	(153)
Loss on sale of property, plant and equipment	492	140
Equity in earnings of WTLPG	(2,726)	(1,758)
Derivative (income) loss	(2,069)	2,392
Net cash received (paid) for commodity derivatives	2,569	(6,429)
Unit-based compensation	520	405
Cash distributions from WTLPG	3,000	2,500
Change in current assets and liabilities, excluding effects of acquisitions and dispositions:
Accounts and other receivables	46,592	29,522
Product exchange receivables	(145)	(13)
Inventories	(15,900)	(19,065)
Due from affiliates	2,632	(9,726)
Other current assets	(699)	(1,372)
Trade and other accounts payable	(17,333)	(4,067)
Product exchange payables	1,264	246
Due to affiliates	(1,897)	(5,774)
Income taxes payable	(110)	(468)
Other accrued liabilities	(5,480)	(2,761)
Change in other non-current assets and liabilities	584	490
Net cash provided by operating activities	58,503	45,788
Cash flows from investing activities:
Payments for property, plant and equipment	(23,566)	(19,756)
Acquisitions	0	(19,533)
Payments for plant turnaround costs	0	(1,591)
Proceeds from sale of property, plant and equipment	98	1,597
Proceeds from repayment of Note receivable - affiliate	0	15,000
Contributions to WTLPG	(12,578)	(145)
Net cash used in investing activities	(36,046)	(24,428)
Cash flows from financing activities:
Payments of long-term debt	(199,000)	(184,000)
Proceeds from long-term debt	218,000	155,000
Proceeds from issuance of common units, net of issuance related costs	(118)	51,071
General partner contribution	0	1,098
Purchase of treasury units	(273)	(4)
Payment of debt issuance costs	(1,240)	(40)
Excess purchase price over carrying value of acquired assets	(26)	(7,887)
Reimbursement of excess purchase price over carrying value of acquired assets	0	1,125
Cash distributions paid	(39,217)	(37,706)
Net cash used in financing activities	(21,874)	(21,343)
Net increase in cash	583	17
Cash at beginning of period	27	15
Cash at end of period	610	32
Non-cash additions to property, plant and equipment	$ 1,811	$ 3,666

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Nature of Operations and Basis of Presentation	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Martin Midstream Partners L.P. (the "Partnership") is a publicly traded limited partnership with a diverse set of operations focused primarily in the United States ("U.S.") Gulf Coast region. Its four primary business lines include: natural gas services, including liquids transportation and distribution services and natural gas storage; terminalling and storage services for petroleum products and by-products including the refining of naphthenic crude oil, blending and packaging of finished lubricants; sulfur and sulfur-based products processing, manufacturing, marketing and distribution; and marine transportation services for petroleum products and by-products. The Partnership’s unaudited consolidated and condensed financial statements have been prepared in accordance with the requirements of Form 10-Q and U.S. Generally Accepted Accounting Principles ("U.S. GAAP") for interim financial reporting. Accordingly, these financial statements have been condensed and do not include all of the information and footnotes required by U.S. GAAP for annual audited financial statements of the type contained in the Partnership’s annual reports on Form 10-K. In the opinion of the management of the Partnership’s general partner, all adjustments and elimination of significant intercompany balances necessary for a fair presentation of the Partnership’s financial position, results of operations, and cash flows for the periods shown have been made. All such adjustments are of a normal recurring nature. Results for such interim periods are not necessarily indicative of the results of operations for the full year. These financial statements should be read in conjunction with the Partnership’s audited consolidated financial statements and notes thereto included in the Partnership’s annual report on Form 10-K for the year ended December 31, 2017, filed with the Securities and Exchange Commission (the "SEC") on February 16, 2018, as amended by Amendment No. 1 on Form 10-K/A for the year ended December 31, 2017 filed on March 29, 2018. Management has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these consolidated and condensed financial statements in conformity with U.S. GAAP. Actual results could differ from those estimates. Correction of Immaterial Error. The second quarter and year to date amounts for 2017 have been revised to reflect a reclassification in the presentation of certain expenses associated with the manufacturing and shipping of product related to a location in the Partnership's Terminalling and Storage operating segment. The reclassification resulted in a decrease in operating expenses from $34,435 to $32,552 and an increase in cost of products sold from $119,419 to $121,302 for the three months ended June 30, 2017, and a decrease in operating expenses from $69,492 to $65,926 and an increase in cost of products sold from $278,527 to $282,093

New Accounting Pronouncements

New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2018
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU replaced most existing revenue recognition guidance in U.S. GAAP. The new standard is effective for the Partnership on January 1, 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Partnership adopted the new standard utilizing the cumulative effect method which will result in the cumulative effect of the adoption being recorded as of January 1, 2018. The Partnership adopted ASU 2014-09 on January 1, 2018 and did not identify any significant changes in the timing of revenue recognition when considering the amended accounting guidance. Additional disclosures related to revenue recognition appear in "Note 5. Revenue." In February 2016, the FASB issued ASU 2016-02, Leases

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Acquisition of Terminalling Assets. On February 22, 2017, the Partnership acquired 100% of the membership interests of MEH South Texas Terminals LLC ("MEH"), a subsidiary of Martin Resource Management, for a purchase price of $27,420 (the "Hondo Acquisition"), which was funded with borrowings under the Partnership's revolving credit facility. At the date of acquisition, MEH was in the process of constructing an asphalt terminal facility in Hondo, Texas (the "Hondo Terminal"), to serve the asphalt market in San Antonio, Texas and surrounding areas. This acquisition is considered a transfer of net assets between entities under common control. The acquisition of these assets was recorded at the historical carrying value of the assets at the acquisition date. The excess of the purchase price over the carrying value of the assets of $7,887 was recorded as an adjustment to "Partners' capital" during the six months ended June 30, 2017. During 2018, the Partnership paid an additional $26 related to a purchase price true-up, which was recorded as a further adjustment to "Partners' capital" for the six months ended June 30, 2018. Original purchase price $ 27,420 Purchase price true-up 26 Historical carrying value of assets allocated to "Property, plant and equipment" 19,533 Excess purchase price over carrying value of acquired assets $ 7,913 As no individual line item of the historical financial statements of the acquired assets was in excess of 3%

Divestitures, Asset Impairments

Divestitures, Asset Impairments, and Discontinued Operations	6 Months Ended
	Jun. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Divestitures, Asset Impairments, and Discontinued Operations	DIVESTITURES, ASSET IMPAIRMENTS, AND DISCONTINUED OPERATIONS Long-Lived Assets Held for Sale At June 30, 2018 and December 31, 2017, certain terminalling and storage and marine transportation assets met the criteria to be classified as held for sale in accordance with ASC 360-10 and are presented at the lower of the assets' carrying amount or fair value less cost to sell by segment in current assets as follows: June 30, 2018 December 31, 2017 Terminalling and storage $ 4,358 $ 4,152 Marine transportation 3,800 5,427 Assets held for sale $ 8,158 $ 9,579

Revenue

Revenue	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE The following table disaggregates our revenue by major source: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Terminalling and storage segment Lubricant product sales $ 36,824 $ 33,413 $ 73,304 $ 65,560 Throughput and storage 24,090 24,695 48,154 49,353 $ 60,914 $ 58,108 $ 121,458 $ 114,913 Natural gas services segment Natural gas liquids product sales $ 90,643 $ 73,666 $ 249,806 $ 200,323 Natural gas storage 13,804 14,838 29,160 29,503 $ 104,447 $ 88,504 $ 278,966 $ 229,826 Sulfur service segment Sulfur product sales $ 10,479 $ 11,193 $ 22,316 $ 24,273 Fertilizer product sales 25,205 20,834 48,268 47,281 Sulfur services 2,787 2,850 5,574 5,700 $ 38,471 $ 34,877 $ 76,158 $ 77,254 Marine transportation segment Inland transportation $ 11,206 $ 11,022 $ 20,898 $ 22,313 Offshore transportation 1,533 1,411 3,295 2,941 $ 12,739 $ 12,433 $ 24,193 $ 25,254 Revenue is measured based on a consideration specified in a contract with a customer and excludes amounts collected on behalf of third parties where the Partnership is acting as an agent. The Partnership recognizes revenue when the Partnership satisfies a performance obligation, which typically occurs when the Partnership transfers control over a product to a customer or as the Partnership delivers a service. The following is a description of the principal activities - separated by reportable segments - from which the Partnership generates revenue. Terminalling and Storage Segment Revenue is recognized for storage contracts based on the contracted monthly tank fixed fee. For throughput contracts, revenue is recognized based on the volume moved through the Partnership’s terminals at the contracted rate. For the Partnership’s tolling agreement, revenue is recognized based on the contracted monthly reservation fee and throughput volumes moved through the facility. When lubricants and drilling fluids are sold by truck or rail, revenue is recognized when title is transfered, which is either upon delivering product to the customer or when the product leaves the Partnership's facility, depending on the specific terms of the contract. Delivery of product is invoiced as the transaction occurs and is generally paid within a month. Natural Gas Services Segment Natural Gas Liquids ("NGL") distribution revenue is recognized when product is delivered by truck, rail, or pipeline to the Partnership's NGL customers. Revenue is recognized on title transfer of the product to the customer. Delivery of product is invoiced as the transaction occurs and are generally paid within a month. Natural gas storage revenue is recognized when the service is provided to the customer. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Sulfur Services Segment Revenue from sulfur product sales is recognized when the customer takes title to the product. Delivery of product is invoiced as the transaction occurs and are generally paid within a month. Revenue from sulfur services is recognized as services are performed during each monthly period. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Marine Transportation Segment Revenue is recognized for time charters based on a per day rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. The table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied at the end of the reporting period. The Partnership applies the practical expedient in ASC 606-10-50-14(a) and does not disclose information about remaining performance obligations that have original expected durations of one year or less. 2018 2019 2020 2021 2022 Thereafter Total Terminalling and storage Storage and throughput $ 25,119 $ 50,629 $ 49,330 $ 46,022 $ 41,505 $ 393,700 $ 606,305 Natural gas services Natural gas storage $ 19,141 $ 32,703 $ 26,935 $ 25,134 $ 24,615 $ 10,107 $ 138,635 Sulfur services Sulfur product sales $ 8,398 $ 16,796 $ 4,898 $ 1,181 $ 295 $ — $ 31,568 Marine transportation Offshore transportation $ 3,128 $ 6,205 $ 6,069 $ — $ — $ — $ 15,402 Total $ 55,786 $ 106,333 $ 87,232 $ 72,337 $ 66,415 $ 403,807 $ 791,910

Inventories

Inventories	6 Months Ended
	Jun. 30, 2018
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Components of inventories at June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 December 31, 2017 Natural gas liquids $ 60,176 $ 47,462 Sulfur 14,542 8,436 Sulfur based products 12,108 18,674 Lubricants 23,488 20,086 Other 2,786 2,594 $ 113,100 $ 97,252

Investment in West Texas LPG Pi

Investment in West Texas LPG Pipeline L.P.	6 Months Ended
	Jun. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investment in West Texas LPG Pipeline L.P.	INVESTMENT IN WEST TEXAS LPG PIPELINE L.P. The Partnership owns a 19.8% limited partnership and 0.2% general partnership interest in West Texas LPG Pipeline L.P. ("WTLPG"). A wholly-owned subsidiary of ONEOK, Inc. is the operator of the assets. WTLPG owns an approximate 2,300 mile common-carrier pipeline system that primarily transports NGLs from New Mexico and Texas to Mont Belvieu, Texas for fractionation. The Partnership recognizes its 20% interest in WTLPG as "Investment in WTLPG" on its Consolidated and Condensed Balance Sheets. The Partnership accounts for its ownership interest in WTLPG under the equity method of accounting. Selected financial information for WTLPG is as follows: As of June 30, Three Months Ended June 30, Six Months Ended June 30, Total Assets Long-Term Debt Members' Equity Revenues Net Income Revenues Net Income 2018 WTLPG $ 917,441 $ — $ 868,112 $ 23,390 $ 5,653 $ 46,431 $ 13,359 As of December 31, 2017 WTLPG $ 837,163 $ — $ 787,426 $ 21,420 $ 4,264 $ 41,139 $ 8,789

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT At June 30, 2018 and December 31, 2017 , long-term debt consisted of the following: June 30, December 31, $664,444 Revolving credit facility at variable interest rate (5.09% 1 weighted average at June 30, 2018), due March 2020 secured by substantially all of the Partnership’s assets, including, without limitation, inventory, accounts receivable, vessels, equipment, fixed assets and the interests in the Partnership’s operating subsidiaries and equity method investees, net of unamortized debt issuance costs of $4,879 and $4,986, respectively 2,3 $ 459,121 $ 440,014 $400,000 Senior notes, 7.25% interest, net of unamortized debt issuance costs of $1,796 and $2,138, respectively, including unamortized premium of $803 and $956, respectively, issued $250,000 February 2013 and $150,000 April 2014, $26,200 repurchased during 2015, due February 2021, unsecured 3,4 372,807 372,618 Total long-term debt, net $ 831,928 $ 812,632 1 Interest rate fluctuates based on the LIBOR rate plus an applicable margin set on the date of each advance. The margin above LIBOR is set every three months. Indebtedness under the credit facility bears interest at LIBOR plus an applicable margin or the base prime rate plus an applicable margin. All amounts outstanding at June 30, 2018 and December 31, 2017 were at LIBOR plus an applicable margin. The applicable margin for revolving loans that are LIBOR loans ranges from 2.00% to 3.00% and the applicable margin for revolving loans that are base prime rate loans ranges from 1.00% to 2.00% . The applicable margin for existing LIBOR borrowings at June 30, 2018 is 3.00% . The credit facility contains various covenants which limit the Partnership’s ability to make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management (the "Omnibus Agreement"). The Partnership is permitted to make quarterly distributions so long as no event of default exists. 2 On February 21, 2018, the Partnership amended its revolving credit facility to, among other things, (i) create an inventory financing sublimit tranche, which is a part of and not in addition to the already existing commitments under the revolving credit facility, under which availability is subject to a borrowing base calculated by reference to eligible petroleum products inventory, (ii) exclude the amount of loans under the inventory financing sublimit tranche from total outstanding indebtedness for purposes of determining leverage ratio covenants under the revolving credit facility, (iii) increase the maximum permitted leverage ratio (as defined in the credit agreement, being generally computed as the ratio of total funded debt to consolidated earnings before interest, taxes, depreciation, amortization and certain other non-cash charges) from 5.25 to 1.00 , with a temporary springing provision to 5.50 to 1.00 under certain scenarios, to 5.75 to 1.00 for the first and second quarters of 2018, 5.50 to 1.00 for the next three quarters and 5.25 to 1.00 , with the temporary springing provision to 5.50 to 1.00 going back into effect, thereafter and (iv) decrease the maximum permitted senior leverage ratio (as defined in the credit agreement, being generally computed as the ratio of total secured funded debt to consolidated earnings before interest, taxes, depreciation, amortization and certain other non-cash charges) from 3.50 to 1.00 to 3.25 to 1.00 . The maximum amount of the inventory financing sublimit tranche is $10,000 during the period between March 1 and June 30 of each year, and $75,000 at all other times during each year. 3 The Partnership is in compliance with all debt covenants as of June 30, 2018 and December 31, 2017 , respectively. 4 The 2021 indenture restricts the Partnership’s ability to sell assets; pay distributions or repurchase units or redeem or repurchase subordinated debt; make investments; incur or guarantee additional indebtedness or issue preferred units; and consolidate, merge or transfer all or substantially all of its assets. The Partnership paid cash interest, net of capitalized interest, in the amount of $6,077 and $4,328 for the three months ended June 30, 2018 and 2017 , respectively. The Partnership paid cash interest, net of capitalized interest, in the amount of $24,955 and $22,509 for the six months ended June 30, 2018 and 2017, respectively. Capitalized interest was $167 and $222 for the three months ended June 30, 2018 and 2017 , respectively. Capitalized interest was $328 and $445 for the six months ended June 30, 2018

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	6 Months Ended
	Jun. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Information	SUPPLEMENTAL BALANCE SHEET INFORMATION Components of "Other assets, net" were as follows: June 30, 2018 December 31, 2017 Customer contracts and relationships, net $ 21,730 $ 25,252 Other intangible assets 1,506 1,752 Other 4,966 5,797 $ 28,202 $ 32,801 Accumulated amortization of intangible assets was $ 44,425 and $ 39,462 at June 30, 2018 and December 31, 2017 , respectively. Components of "Other accrued liabilities" were as follows: June 30, 2018 December 31, 2017 Accrued interest $ 11,985 $ 11,726 Asset retirement obligations 3,374 5,429 Property and other taxes payable 5,310 5,638 Accrued payroll 2,419 3,385 Other 5 162 $ 23,093 $ 26,340 The schedule below summarizes the changes in our asset retirement obligations: June 30, 2018 Beginning asset retirement obligations $ 13,512 Revisions to existing liabilities 1 4,756 Accretion expense 261 Liabilities settled (4,670 ) Ending asset retirement obligations 13,859 Current portion of asset retirement obligations 2 (3,374 ) Long-term portion of asset retirement obligations 3 $ 10,485 1 Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining useful life of the assets. The 2018 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets. 2 The current portion of asset retirement obligations is included in "Other current liabilities" on the Partnership's Consolidated and Condensed Balance Sheets. 3

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Partnership’s revenues and cost of products sold are materially impacted by changes in NGL prices. Additionally, the Partnership's results of operations are materially impacted by changes in interest rates. In an effort to manage its exposure to these risks, the Partnership periodically enters into various derivative instruments, including commodity and interest rate hedges. All derivatives and hedging instruments are non-hedge derivatives and are included on the balance sheet as an asset or a liability measured at fair value and changes in fair value are recognized as gains and losses in earnings of the periods in which they occur. (a) Commodity Derivative Instruments The Partnership from time to time has used derivatives to manage the risk of commodity price fluctuation. Commodity risk is the adverse effect on the value of a liability or future purchase that results from a change in commodity price. The Partnership has established a hedging policy and monitors and manages the commodity market risk associated with potential commodity risk exposure. In addition, the Partnership has focused on utilizing counterparties for these transactions whose financial condition is appropriate for the credit risk involved in each specific transaction. The Partnership has entered into hedging transactions as of June 30, 2018 to protect a portion of its commodity price risk exposure. These hedging arrangements are in the form of swaps for NGLs. The Partnership has instruments totaling a gross notional quantity of 360 barrels settling during the period from October 1, 2018 through December 31, 2018. At December 31, 2017, the Partnership had instruments totaling a gross notional quantity of 145 barrels settling during the period from January 31, 2018 through February 28, 2018. These instruments settle against the applicable pricing source for each grade and location. (b) Interest Rate Derivative Instruments The Partnership is exposed to market risks associated with interest rates. Market risk is the adverse effect on the value of a financial instrument that results from a change in interest rates. We minimize this market risk by establishing and monitoring parameters that limit the types and degree of market risk that may be undertaken. From time to time, the Partnership enters into interest rate swaps to manage interest rate risk associated with the Partnership’s variable rate credit facility and its fixed rate senior unsecured notes. At June 30, 2018 and 2017, the Partnership did not have any outstanding interest rate derivative instruments. For information regarding gains and losses on interest rate derivative instruments, see "Tabular Presentation of Gains and Losses on Derivative Instruments" below. (c) Tabular Presentation of Gains and Losses on Derivative Instruments The following table summarizes the fair value and classification of the Partnership’s derivative instruments in its Consolidated and Condensed Balance Sheets: Fair Values of Derivative Instruments in the Consolidated and Condensed Balance Sheets Derivative Assets Derivative Liabilities Fair Values Fair Values Balance Sheet Location June 30, 2018 December 31, 2017 Balance Sheet Location June 30, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Current: Commodity contracts Fair value of derivatives $ — $ — Fair value of derivatives $ 572 $ 72 Total derivatives not designated as hedging instruments $ — $ — $ 572 $ 72 Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Three Months Ended June 30, 2018 and 2017 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2018 2017 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ (401 ) $ 103 Total effect of derivatives not designated as hedging instruments $ (401 ) $ 103 Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Six Months Ended June 30, 2018 and 2017 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2018 2017 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ 2,069 $ (2,392 ) Total effect of derivatives not designated as hedging instruments $ 2,069 $ (2,392 )

Partners' Capital

Partners' Capital	6 Months Ended
	Jun. 30, 2018
Partners' Capital Notes [Abstract]
Partners' Capital	PARTNERS' CAPITAL As of June 30, 2018 , Partners’ capital consisted of 39,052,237 common limited partner units, representing a 98% partnership interest, and a 2% general partner interest. Martin Resource Management, through subsidiaries, owns 6,114,532 of the Partnership's common limited partner units representing approximately 15.7% of the Partnership's outstanding common limited partner units. Martin Midstream GP LLC ("MMGP"), the Partnership's general partner, owns the 2% general partnership interest. Martin Resource Management controls the Partnership's general partner, by virtue of its 51% voting interest in MMGP Holdings, LLC ("Holdings"), the sole member of the Partnership's general partner. The partnership agreement of the Partnership (the "Partnership Agreement") contains specific provisions for the allocation of net income and losses to each of the partners for purposes of maintaining their respective partner capital accounts. Issuance of Common Units On February 22, 2017, the Partnership completed a public offering of 2,990,000 common units at a price of $18.00 per common unit, before the payment of underwriters' discounts, commissions and offering expenses (per unit value is in dollars, not thousands). Total proceeds from the sale of the 2,990,000 common units, net of underwriters' discounts, commissions and offering expenses, were $51,071 . Additionally, the Partnership's general partner contributed $1,098 in cash to the Partnership in conjunction with the issuance in order to maintain its 2.0% general partner interest in the Partnership. All of the net proceeds were used to pay down outstanding amounts under the Partnership's revolving credit facility. Incentive Distribution Rights MMGP holds a 2% general partner interest and certain incentive distribution rights ("IDRs") in the Partnership. IDRs are a separate class of non-voting limited partner interest that may be transferred or sold by the general partner under the terms of the Partnership Agreement, and represent the right to receive an increasing percentage of cash distributions after the minimum quarterly distribution and any cumulative arrearages on common units once certain target distribution levels have been achieved. The Partnership is required to distribute all of its available cash from operating surplus, as defined in the Partnership Agreement. The general partner was allocated no incentive distributions during the three or six months ended June 30, 2018 and 2017. The target distribution levels entitle the general partner to receive 2% of quarterly cash distributions from the minimum of $0.50 per unit up to $0.55 per unit, 15% of quarterly cash distributions in excess of $0.55 per unit until all unitholders have received $0.625 per unit, 25% of quarterly cash distributions in excess of $0.625 per unit until all unitholders have received $0.75 per unit and 50% of quarterly cash distributions in excess of $0.75 per unit. Distributions of Available Cash The Partnership distributes all of its available cash (as defined in the Partnership Agreement) within 45 days after the end of each quarter to unitholders of record and to the general partner. Available cash is generally defined as all cash and cash equivalents of the Partnership on hand at the end of each quarter less the amount of cash reserves its general partner determines in its reasonable discretion is necessary or appropriate to: (i) provide for the proper conduct of the Partnership’s business; (ii) comply with applicable law, any debt instruments or other agreements; or (iii) provide funds for distributions to unitholders and the general partner for any one or more of the next four quarters, plus all cash on the date of determination of available cash for the quarter resulting from working capital borrowings made after the end of the quarter. Net Income per Unit The Partnership follows the provisions of the FASB ASC 260-10 related to earnings per share, which addresses the application of the two-class method in determining income per unit for master limited partnerships having multiple classes of securities that may participate in partnership distributions accounted for as equity distributions. Undistributed earnings are allocated to the general partner and limited partners utilizing the contractual terms of the Partnership Agreement. Distributions to the general partner pursuant to the IDRs are limited to available cash that will be distributed as defined in the Partnership Agreement. Accordingly, the Partnership does not allocate undistributed earnings to the general partner for the IDRs because the general partner's share of available cash is the maximum amount that the general partner would be contractually entitled to receive if all earnings for the period were distributed. When current period distributions are in excess of earnings, the excess distributions for the period are to be allocated to the general partner and limited partners based on their respective sharing of income and losses specified in the Partnership Agreement. Additionally, as required under FASB ASC 260-10-45-61A, unvested share-based payments that entitle employees to receive non-forfeitable distributions are considered participating securities, as defined in FASB ASC 260-10-20, for earnings per unit calculations. For purposes of computing diluted net income per unit, the Partnership uses the more dilutive of the two-class and if-converted methods. Under the if-converted method, the weighted-average number of subordinated units outstanding for the period is added to the weighted-average number of common units outstanding for purposes of computing basic net income per unit and the resulting amount is compared to the diluted net income per unit computed using the two-class method. The following is a reconciliation of net income allocated to the general partner and limited partners for purposes of calculating net income attributable to limited partners per unit: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net income (loss) $ (7,246 ) $ 989 $ 5,572 $ 14,572 Less general partner’s interest in net income (loss): Distributions payable on behalf of IDRs — — — — Distributions payable on behalf of general partner interest 392 393 784 785 General partner interest in undistributed loss (537 ) (374 ) (673 ) (494 ) Less income (loss) allocable to unvested restricted units (6 ) 3 2 38 Limited partners’ interest in net income (loss) $ (7,095 ) $ 967 $ 5,459 $ 14,243 The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Basic weighted average limited partner units outstanding 38,722,037 38,357,293 38,828,845 37,842,140 Dilutive effect of restricted units issued — 56,618 5,576 52,476 Total weighted average limited partner diluted units outstanding 38,722,037 38,413,911 38,834,421 37,894,616

Unit Based Awards

Unit Based Awards	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit Based Awards	UNIT BASED AWARDS The Partnership recognizes compensation cost related to unit-based awards to employees in its consolidated financial statements in accordance with certain provisions of ASC 718. The Partnership recognizes compensation costs related to unit-based awards to directors under certain provisions of ASC 505-50-55 related to equity-based payments to non-employees. Amounts recognized in selling, general, and administrative expense in the consolidated and condensed financial statements with respect to these plans are as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Employees $ 345 $ 182 $ 441 $ 341 Non-employee directors 43 37 79 64 Total unit-based compensation expense $ 388 $ 219 $ 520 $ 405 All of the Partnership's outstanding awards at June 30, 2018 met the criteria to be treated under equity classification. Long-Term Incentive Plans The Partnership's general partner has a long-term incentive plan for employees and directors of the general partner and its affiliates who perform services for the Partnership. On May 26, 2017, the unitholders of the Partnership approved the Martin Midstream Partners L.P. 2017 Restricted Unit Plan (the "2017 LTIP"). The plan currently permits the grant of awards covering an aggregate of 3,000,000 common units, all of which can be awarded in the form of restricted units. The plan is administered by the compensation committee of the general partner’s board of directors (the "Compensation Committee"). A restricted unit is a unit that is granted to grantees with certain vesting restrictions, which may be time-based and/or performance-based. Once these restrictions lapse, the grantee is entitled to full ownership of the unit without restrictions. The Compensation Committee may determine to make grants under the plan containing such terms as the Compensation Committee shall determine under the plan. With respect to time-based restricted units ("TBRU's"), the Compensation Committee will determine the time period over which restricted units granted to employees and directors will vest. The Compensation Committee may also award a percentage of restricted units with vesting requirements based upon the achievement of specified pre-established performance targets ("Performance Based Restricted Units" or "PBRU's"). The performance targets may include, but are not limited to, the following: revenue and income measures, cash flow measures, net income before interest expense and income tax expense ("EBIT"), net income before interest expense, income tax expense, and depreciation and amortization ("EBITDA"), distribution coverage metrics, expense measures, liquidity measures, market measures, corporate sustainability metrics, and other measures related to acquisitions, dispositions, operational objectives and succession planning objectives. PBRU's are earned only upon our achievement of an objective performance measure for the performance period. PBRU's which vest are payable in common units. Unvested units granted under the 2017 LTIP may or may not participate in cash distributions depending on the terms of each individual award agreement. The restricted units issued to directors generally vest in equal annual installments over a four -year period. Restricted units issued to employees generally vest in equal annual installments over three years of service. On February 20, 2018, the Partnership issued 4,650 TBRU's to each of the Partnership's three independent directors under the 2017 LTIP. These restricted common units vest in equal installments of 1,162.5 units on January 24, 2019, 2020, 2021, and 2022. On March 1, 2018, the Partnership issued 301,550 TBRU's and 317,925 PBRU's to certain employees of Martin Resource Management. The TBRU's vest in equal installments over a three-year service period. The PBRU's will vest at the conclusion of a three-performance period based on certain performance targets. In addition, the PBRU's awarded on March 1, 2018 that are achieved will only vest if the grantee is employed by Martin Resource Management on March 31, 2021. As of June 30, 2018, the Partnership is unable to ascertain if the performance conditions will be achieved and, as such, has not recognized compensation expense for the vesting of the units. The Partnership will record compensation expense for the vested portion of the units once the achievement of the performance condition is deemed probable. The restricted units are valued at their fair value at the date of grant which is equal to the market value of common units on such date. A summary of the restricted unit activity for the six months ended June 30, 2018 is provided below: Number of Units Weighted Average Grant-Date Fair Value Per Unit Non-vested, beginning of period 98,750 $ 24.80 Granted (TBRU) 315,500 $ 13.89 Granted (PBRU) 317,925 $ 13.89 Vested (80,550 ) $ 27.71 Forfeited (7,000 ) $ 13.90 Non-Vested, end of period 644,625 $ 13.91 Aggregate intrinsic value, end of period $ 8,896 A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the six months ended June 30, 2018 and 2017 is provided below: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Aggregate intrinsic value of units vested $ — $ 10 $ 1,188 $ 135 Fair value of units vested — 20 2,232 190 As of June 30, 2018 , there was $4,052 of unrecognized compensation cost related to non-vested restricted units. That cost is expected to be recognized over a weighted-average period of 2.84

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS As of June 30, 2018 , Martin Resource Management owns 6,114,532 of the Partnership’s common units representing approximately 15.7% of the Partnership’s outstanding limited partner units. Martin Resource Management controls the Partnership's general partner by virtue of its 51% voting interest in Holdings, the sole member of the Partnership's general partner. The Partnership’s general partner, MMGP, owns a 2% general partner interest in the Partnership and the Partnership’s IDRs. The Partnership’s general partner’s ability, as general partner, to manage and operate the Partnership, and Martin Resource Management’s ownership as of June 30, 2018 , of approximately 15.7% of the Partnership’s outstanding limited partner units, effectively gives Martin Resource Management the ability to veto some of the Partnership’s actions and to control the Partnership’s management. The following is a description of the Partnership’s material related party agreements and transactions: Omnibus Agreement Omnibus Agreement . The Partnership and its general partner are parties to the Omnibus Agreement dated November 1, 2002, with Martin Resource Management that governs, among other things, potential competition and indemnification obligations among the parties to the agreement, related party transactions, the provision of general administration and support services by Martin Resource Management and the Partnership’s use of certain Martin Resource Management trade names and trademarks. The Omnibus Agreement was amended on November 25, 2009, to include processing crude oil into finished products including naphthenic lubricants, distillates, asphalt and other intermediate cuts. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management. Non-Competition Provisions . Martin Resource Management has agreed for so long as it controls the general partner of the Partnership, not to engage in the business of: • providing terminalling and storage services for petroleum products and by-products including the refining, blending and packaging of finished lubricants; • providing marine transportation of petroleum products and by-products; • distributing NGLs; and • manufacturing and selling sulfur-based fertilizer products and other sulfur-related products. This restriction does not apply to: • the ownership and/or operation on the Partnership’s behalf of any asset or group of assets owned by it or its affiliates; • any business operated by Martin Resource Management, including the following: ◦ providing land transportation of various liquids; ◦ distributing fuel oil, marine fuel and other liquids; ◦ providing marine bunkering and other shore-based marine services in Texas, Louisiana, Mississippi, Alabama, and Florida; ◦ operating a crude oil gathering business in Stephens, Arkansas; ◦ providing crude oil gathering, refining, and marketing services of base oils, asphalt, and distillate products in Smackover, Arkansas; ◦ providing crude oil marketing and transportation from the well head to the end market; ◦ operating an environmental consulting company; ◦ operating an engineering services company; ◦ supplying employees and services for the operation of the Partnership's business; and ◦ operating, solely for the Partnership's account, the asphalt facilities in Omaha, Nebraska, Port Neches, Texas, Hondo, Texas, and South Houston, Texas. • any business that Martin Resource Management acquires or constructs that has a fair market value of less than $5,000 ; • any business that Martin Resource Management acquires or constructs that has a fair market value of $5,000 or more if the Partnership has been offered the opportunity to purchase the business for fair market value and the Partnership declines to do so with the concurrence of the conflicts committee of the board of directors of the general partner of the Partnership (the "Conflicts Committee"); and • any business that Martin Resource Management acquires or constructs where a portion of such business includes a restricted business and the fair market value of the restricted business is $5,000 or more and represents less than 20% of the aggregate value of the entire business to be acquired or constructed; provided that, following completion of the acquisition or construction, the Partnership will be provided the opportunity to purchase the restricted business. Services. Under the Omnibus Agreement, Martin Resource Management provides the Partnership with corporate staff, support services, and administrative services necessary to operate the Partnership’s business. The Omnibus Agreement requires the Partnership to reimburse Martin Resource Management for all direct expenses it incurs or payments it makes on the Partnership’s behalf or in connection with the operation of the Partnership’s business. There is no monetary limitation on the amount the Partnership is required to reimburse Martin Resource Management for direct expenses. In addition to the direct expenses, under the Omnibus Agreement, the Partnership is required to reimburse Martin Resource Management for indirect general and administrative and corporate overhead expenses. Effective January 1, 2018, through December 31, 2018, the Conflicts Committee approved an annual reimbursement amount for indirect expenses of $16,416 . The Partnership reimbursed Martin Resource Management for $4,104 and $4,104 of indirect expenses for the three months ended June 30, 2018 and 2017 , respectively. The Partnership reimbursed Martin Resource Management for $8,208 and $8,208 of indirect expenses for the six months ended June 30, 2018 and 2017 , respectively. The Conflicts Committee will review and approve future adjustments in the reimbursement amount for indirect expenses, if any, annually. These indirect expenses are intended to cover the centralized corporate functions Martin Resource Management provides for the Partnership, such as accounting, treasury, clerical, engineering, legal, billing, information technology, administration of insurance, general office expenses and employee benefit plans and other general corporate overhead functions the Partnership shares with Martin Resource Management retained businesses. The provisions of the Omnibus Agreement regarding Martin Resource Management’s services will terminate if Martin Resource Management ceases to control the general partner of the Partnership. Related Party Transactions . The Omnibus Agreement prohibits the Partnership from entering into any material agreement with Martin Resource Management without the prior approval of the Conflicts Committee. For purposes of the Omnibus Agreement, the term "material agreements" means any agreement between the Partnership and Martin Resource Management that requires aggregate annual payments in excess of the then-applicable agreed upon reimbursable amount of indirect general and administrative expenses. Please read "Services" above. License Provisions. Under the Omnibus Agreement, Martin Resource Management has granted the Partnership a nontransferable, nonexclusive, royalty-free right and license to use certain of its trade names and marks, as well as the trade names and marks used by some of its affiliates. Amendment and Termination. The Omnibus Agreement may be amended by written agreement of the parties; provided, however, that it may not be amended without the approval of the Conflicts Committee if such amendment would adversely affect the unitholders. The Omnibus Agreement was first amended on November 25, 2009, to permit the Partnership to provide refining services to Martin Resource Management. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management. Such amendments were approved by the Conflicts Committee. The Omnibus Agreement, other than the indemnification provisions and the provisions limiting the amount for which the Partnership will reimburse Martin Resource Management for general and administrative services performed on its behalf, will terminate if the Partnership is no longer an affiliate of Martin Resource Management. Motor Carrier Agreement Motor Carrier Agreement. The Partnership is a party to a motor carrier agreement effective January 1, 2006, as amended, with Martin Transport, Inc., a wholly owned subsidiary of Martin Resource Management through which Martin Transport, Inc. operates its land transportation operations. Under the agreement, Martin Transport, Inc. agreed to transport the Partnership's NGLs as well as other liquid products. Term and Pricing. The agreement has an initial term that expired in December 2007 but automatically renews for consecutive one year periods unless either party terminates the agreement by giving written notice to the other party at least 30 days prior to the expiration of the then-applicable term. The Partnership has the right to terminate this agreement at any time by providing 90 days prior notice. These rates are subject to any adjustments which are mutually agreed upon or in accordance with a price index. Additionally, during the term of the agreement, shipping charges are also subject to fuel surcharges determined on a weekly basis in accordance with the U.S. Department of Energy’s national diesel price list. Indemnification. Martin Transport, Inc. has indemnified the Partnership against all claims arising out of the negligence or willful misconduct of Martin Transport, Inc. and its officers, employees, agents, representatives and subcontractors. The Partnership has indemnified Martin Transport, Inc. against all claims arising out of the negligence or willful misconduct of the Partnership and its officers, employees, agents, representatives and subcontractors. In the event a claim is the result of the joint negligence or misconduct of Martin Transport, Inc. and the Partnership, indemnification obligations will be shared in proportion to each party’s allocable share of such joint negligence or misconduct. Marine Agreements Marine Transportation Agreement. The Partnership is a party to a marine transportation agreement effective January 1, 2006, as amended, under which the Partnership provides marine transportation services to Martin Resource Management on a spot-contract basis at applicable market rates. Effective each January 1, this agreement automatically renews for consecutive one year periods unless either party terminates the agreement by giving written notice to the other party at least 60 days prior to the expiration of the then applicable term. The fees the Partnership charges Martin Resource Management are based on applicable market rates. Marine Fuel. The Partnership is a party to an agreement with Martin Resource Management dated November 1, 2002, under which Martin Resource Management provides the Partnership with marine fuel from its locations in the Gulf of Mexico at a fixed rate in excess of the Platt’s U.S. Gulf Coast Index for #2 Fuel Oil. Under this agreement, the Partnership agreed to purchase all of its marine fuel requirements that occur in the areas serviced by Martin Resource Management. Terminal Services Agreements Diesel Fuel Terminal Services Agreement. Effective January 1, 2016, the Partnership entered into a second amended and restated terminalling services agreement under which the Partnership provides terminal services to Martin Resource Management for marine fuel distribution. At such time, the per gallon throughput fee the Partnership charged under this agreement was increased when compared to the previous agreement and may be adjusted annually based on a price index. This agreement was further amended on January 1, 2017 and October 1, 2017 to modify its minimum throughput requirements and throughput fees. This agreement, as amended, continues until September 30, 2018 and thereafter on a month to month basis until terminated by either party by giving 60 days’ written notice. Miscellaneous Terminal Services Agreements. The Partnership is currently party to several terminal services agreements and from time to time the Partnership may enter into other terminal service agreements for the purpose of providing terminal services to related parties. Individually, each of these agreements is immaterial but when considered in the aggregate they could be deemed material. These agreements are throughput based with a minimum volume commitment. Generally, the fees due under these agreements are adjusted annually based on a price index. Other Agreements Cross Tolling Agreement. The Partnership is a party to an amended and restated tolling agreement with Cross Oil Refining and Marketing, Inc. ("Cross") dated October 28, 2014, under which the Partnership processes crude oil into finished products, including naphthenic lubricants, distillates, asphalt and other intermediate cuts for Cross. The tolling agreement expires November 25, 2031. Under this tolling agreement, Cross agreed to process a minimum of 6,500 barrels per day of crude oil at the facility at a fixed price per barrel. Any additional barrels are processed at a modified price per barrel. In addition, Cross agreed to pay a monthly reservation fee and a periodic fuel surcharge fee based on certain parameters specified in the tolling agreement. All of these fees (other than the fuel surcharge) are subject to escalation annually based upon the greater of 3% or the increase in the Consumer Price Index for a specified annual period. In addition, on the third, sixth and ninth anniversaries of the agreement, the parties can negotiate an upward or downward adjustment in the fees subject to their mutual agreement. Sulfuric Acid Sales Agency Agreement . The Partnership was previously a party to a third amended and restated sulfuric acid sales agency agreement dated August 2, 2017 but effective October 1, 2017, under which a successor in interest to the agreement from Martin Resource Management, Saconix LLC ("Saconix"), a limited liability company in which Martin Resource Management held a minority equity interest, purchased and marketed the sulfuric acid produced by the Partnership’s sulfuric acid production plant at Plainview, Texas, that was not consumed by the Partnership’s internal operations. This agreement, as amended, was to remain in place until September 30, 2020 and automatically renew year to year thereafter until either party provided 90 days’ written notice of termination prior to the expiration of the then existing term. Under this agreement, the Partnership sold all of its excess sulfuric acid to Saconix, who then marketed and sold such acid to third-parties. The Partnership shared in the profit of such sales. Effective May 31, 2018, Martin Resource Management no longer holds an equity interest in Saconix. These transactions are reported below as related party transactions during the period the equity interest was held. Transactions subsequent to Martin Resource Managements disposition of the equity interest will be reported as third party transactions. Other Miscellaneous Agreements. From time to time the Partnership enters into other miscellaneous agreements with Martin Resource Management for the provision of other services or the purchase of other goods. The tables below summarize the related party transactions that are included in the related financial statement captions on the face of the Partnership’s Consolidated and Condensed Statements of Operations. The revenues, costs and expenses reflected in these tables are tabulations of the related party transactions that are recorded in the corresponding captions of the consolidated and condensed financial statements and do not reflect a statement of profits and losses for related party transactions. The impact of related party revenues from sales of products and services is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenues: Terminalling and storage $ 20,507 $ 20,331 $ 40,532 $ 40,035 Marine transportation 4,105 4,187 7,718 8,512 Natural gas services — 6 — 118 Product sales: Natural gas services 18 — 19 942 Sulfur services 226 587 612 1,018 Terminalling and storage 182 137 437 194 426 724 1,068 2,154 $ 25,038 $ 25,248 $ 49,318 $ 50,819 The impact of related party cost of products sold is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Cost of products sold: Natural gas services $ 3,099 $ 2,909 $ 7,417 $ 11,803 Sulfur services 4,345 3,767 8,871 7,442 Terminalling and storage 8,009 4,119 14,567 9,186 $ 15,453 $ 10,795 $ 30,855 $ 28,431 The impact of related party operating expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Operating expenses: Marine transportation $ 6,000 $ 6,067 $ 11,321 $ 12,063 Natural gas services 2,232 2,233 4,431 4,468 Sulfur services 1,492 1,534 2,831 2,980 Terminalling and storage 4,615 6,618 9,140 13,317 $ 14,339 $ 16,452 $ 27,723 $ 32,828 The impact of related party selling, general and administrative expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Selling, general and administrative: Marine transportation $ 7 $ 7 $ 15 $ 15 Natural gas services 1,025 1,202 3,279 3,479 Sulfur services 660 621 1,319 1,257 Terminalling and storage 690 566 1,371 1,109 Indirect, including overhead allocation 4,116 4,104 8,235 8,208 $ 6,498 $ 6,500 $ 14,219 $ 14,068 Other Related Party Transactions The Partnership had a $15,000 note receivable from an affiliate of Martin Resource Management which previously bore an annual interest rate of 15% and had a maturity date of August 31, 2026, the balance of which could be prepaid on or after September 1, 2016. On February 14, 2017, the Partnership notified Martin Resource Management that it would be requesting voluntary repayment of the long-term Note Receivable plus accrued interest. During second quarter of 2017, the Note Receivable was fully repaid. The note has historically been recorded in "Note receivable - affiliates" on the Partnership's Consolidated and Condensed Balance Sheets. Interest income for the three months ended June 30, 2018 and 2017 was $0 and $388 , respectively, and is included in "Interest expense, net" in the Consolidated and Condensed Statements of Operations. Interest income for the six months ended June 30, 2018 and 2017 was $0 and $943

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS The Partnership has four reportable segments: natural gas services, terminalling and storage, sulfur services and marine transportation. The Partnership’s reportable segments are strategic business units that offer different products and services. The operating income of these segments is reviewed by the chief operating decision maker to assess performance and make business decisions. The accounting policies of the operating segments are the same as those described in Note 2 in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2017 , filed with the SEC on February 16, 2018, as amended, by Amendment No. 1 on Form 10-K/A filed on March 29, 2018. The Partnership evaluates the performance of its reportable segments based on operating income. There is no allocation of administrative expenses or interest expense. Three Months Ended June 30, 2018 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 62,314 $ (1,400 ) $ 60,914 $ 11,690 $ 1,739 $ 2,471 Natural gas services 104,447 — 104,447 5,304 3,727 2,043 Sulfur services 38,471 — 38,471 2,086 3,048 966 Marine transportation 13,168 (429 ) 12,739 1,811 1,353 2,827 Indirect selling, general and administrative — — — — (4,346 ) — Total $ 218,400 $ (1,829 ) $ 216,571 $ 20,891 $ 5,521 $ 8,307 Three Months Ended June 30, 2017 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 59,561 $ (1,453 ) $ 58,108 $ 10,327 $ 3,252 $ 8,634 Natural gas services 88,504 — 88,504 6,205 4,424 4,383 Sulfur services 34,877 — 34,877 2,030 6,295 862 Marine transportation 13,144 (711 ) 12,433 1,764 1,149 1 Indirect selling, general and administrative — — — — (4,272 ) — Total $ 196,086 $ (2,164 ) $ 193,922 $ 20,326 $ 10,848 $ 13,880 Six Months Ended June 30, 2018 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 124,297 $ (2,839 ) $ 121,458 $ 21,849 $ 4,461 $ 4,592 Natural gas services 278,966 — 278,966 10,605 21,138 3,052 Sulfur services 76,158 — 76,158 4,150 10,040 2,514 Marine transportation 25,196 (1,003 ) 24,193 3,497 2,516 11,118 Indirect selling, general and administrative — — — — (8,577 ) — Total $ 504,617 $ (3,842 ) $ 500,775 $ 40,101 $ 29,578 $ 21,276 Six Months Ended June 30, 2017 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 118,139 $ (3,226 ) $ 114,913 $ 25,804 $ 1,151 $ 16,097 Natural gas services 229,826 — 229,826 12,366 22,697 5,235 Sulfur services 77,254 — 77,254 4,063 17,062 1,167 Marine transportation 26,558 (1,304 ) 25,254 3,429 2,378 695 Indirect selling, general and administrative — — — — (8,692 ) — Total $ 451,777 $ (4,530 ) $ 447,247 $ 45,662 $ 34,596 $ 23,194 The Partnership's assets by reportable segment as of June 30, 2018 and December 31, 2017 , are as follows: June 30, 2018 December 31, 2017 Total assets: Terminalling and storage $ 319,619 $ 326,920 Natural gas services 669,531 704,524 Sulfur services 121,452 120,790 Marine transportation 108,163 101,264 Total assets $ 1,218,765 $ 1,253,498

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITTMENTS AND CONTINGENCIES Contingencies From time to time, the Partnership is subject to various claims and legal actions arising in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on the Partnership. Pursuant to a Purchase Price Reimbursement Agreement between the Partnership and Martin Resource Management related to the Partnership’s acquisition of the Redbird Gas Storage LLC ("Redbird") Class A interests on October 2, 2012, beginning in the second quarter of 2015, Martin Resource Management has reimbursed the Partnership $750 per quarter for four consecutive quarters as a reduction in the purchase price of the Redbird Class A interests. These payments were the result of Cardinal Gas Storage Partners LLC ("Cardinal") not achieving certain financial targets set forth in the Purchase Price Reimbursement Agreement. These payments were considered to be a reduction of the excess of the purchase price over the carrying value of the assets transferred to the Partnership from Martin Resource Management and were recorded as an adjustment to "Partners' capital" in each quarter in which the payments were made. The agreement further provided for purchase price reimbursements of up to $4,500 in 2016 in the event certain financial conditions were not met. For the six months ended June 30, 2017, the Partnership received $1,125 , related to the Purchase Price Reimbursement Agreement. The amount received in the first quarter of 2017 represented the final payment under the Purchase Price Reimbursement Agreement. Certain shippers filed complaints with the Railroad Commission of Texas ("RRC") challenging the increased rates WTLPG implemented effective July 1, 2015. The complainants requested that the rate increase be suspended until the RRC has determined appropriate new rates. On March 8, 2016, the RRC issued an order directing that WTLPG’s rates "in effect prior to July 1, 2015, are the lawful rates for the duration of this docket unless changed by Commission order." A hearing on the merits was held in front of a hearings examiner during the week of March 27, 2017. The hearings examiner issued a Proposal for Decision on September 29, 2017. On December 5, 2017, this matter was brought before the RRC. After brief discussion, the RRC determined that more time was needed to review the proposal for decision and placed the matter on the agenda for the RRC’s January 23, 2018 meeting. At that meeting, the RRC voted to remand the case to the hearings examiner for the limited purpose of admitting and considering additional relevant evidence on competition. The remand hearing is currently scheduled for the week of October 29th of 2018. In 2015, the Partnership was named as a defendant in the cause J. A. Davis Properties, LLC v. Martin Operating Partnership L.P., in the 38th Judicial District Court, Cameron Parish, Louisiana. The plaintiff alleged that the Partnership breached a lease agreement by failing to perform work to the plaintiff's property as required under the lease agreement. The plaintiff originally sought to evict the Partnership from the leased property and to recover damages. Prior to trial, this matter was settled for a confidential amount in September of 2017. The Partnership's financial statements reflect the terms of the settlement and all amounts have been accrued as asset retirement obligations. On December 31, 2015, the Partnership received a demand from a customer in its lubricants packaging business for defense and indemnity in connection with lawsuits filed against it in various United States District Courts, which generally allege that the customer engaged in unlawful and deceptive business practices in connection with its marketing and advertising of its private label motor oil. The Partnership disputes that it has any obligation to defend or indemnify the customer for its conduct. Accordingly, on January 7, 2016, the Partnership filed a Complaint for Declaratory Judgment in the Chancery Court of Davidson County, Tennessee requesting a judicial determination that the Partnership does not owe the customer the demanded defense and indemnity obligations. The lawsuits against the customer have been transferred to the United States District Court for the Western District of Missouri for consolidated pretrial proceedings. On March 1, 2017, at the request of the parties, the Chancery Court of Davidson County, Tennessee administratively closed the Partnership's lawsuit pending rulings in the United States District Court for the Western District of Missouri. In the event that either party moves the Chancery Court of Davidson County, Tennessee to reopen the case, we expect the Court would grant such motion and reopen the case. If the case is reopened, we are currently unable to determine the exposure we may have in this matter, if any. Commitments The Partnership has non-cancelable revenue arrangements that are not under the scope of ASC 606 whereby we have committed certain terminalling and storage assets in exchange for a minimum fee. Future minimum revenues the Partnership expects to receive under these non-cancelable arrangements as of June 30, 2018, are as follows: 2018 - $11,691 ; 2019 - $19,315 ; 2020 - $17,577 ; 2021 - $15,681 ; 2022 - $15,681 ; subsequent years - $73,299

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that reflect the entity's own assumptions and are not corroborated by market data. Assets and liabilities measured at fair value on a recurring basis are summarized below: Level 2 June 30, 2018 December 31, 2017 Commodity derivative contracts, net $ (572 ) $ (72 ) The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument: • Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments. • Note receivable and long-term debt: The carrying amount of the revolving credit facility approximates fair value due to the debt having a variable interest rate and is in Level 2. The Partnership has not had any indicators which represent a change in the market spread associated with its variable interest rate debt. The estimated fair value of the senior unsecured notes is considered Level 1, as the fair value is based on quoted market prices in active markets. June 30, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value 2021 Senior unsecured notes $ 372,807 $ 370,245 $ 372,618 $ 381,657

Condensed Consolidated Financia

Condensed Consolidated Financial Information	6 Months Ended
	Jun. 30, 2018
Consolidating Financial Statements [Abstract]
Condensed Consolidated Financial Information	CONDENSED CONSOLIDATED FINANCIAL INFORMATION

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Quarterly Distribution. On July 19, 2018, the Partnership declared a quarterly cash distribution of $0.50 per common unit for the second quarter of 2018, or $2.00 per common unit on an annualized basis, which will be paid on August 14, 2018 to unitholders of record as of August 7, 2018. Divestiture of WTLPG Partnership Interest. The Partnership has entered into a definitive agreement with ONEOK, Inc. to sell its 20 percent non-operating partnership interest in WTLPG for $195,000 . The Partnership expects to receive net proceeds of approximately $193,650 after transaction fees and expenses. The proceeds from the sale will be used to reduce outstanding borrowings under the Partnership’s revolving credit facility. In conjunction with the proposed sale of West Texas LPG Pipeline, subject to completion of the sale, the Partnership has amended its revolving credit facility which will include, among other things, a revision to the Partnership's existing leverage covenants under its revolving credit facility. Total Indebtedness to EBITDA and Senior Secured Indebtedness to EBITDA (each as defined in the credit agreement) will be amended to 5.25 times and 3.50 times, respectively. No changes to the Consolidated Interest Coverage Ratio (as defined in the credit agreement) of 2.50

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU replaced most existing revenue recognition guidance in U.S. GAAP. The new standard is effective for the Partnership on January 1, 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Partnership adopted the new standard utilizing the cumulative effect method which will result in the cumulative effect of the adoption being recorded as of January 1, 2018. The Partnership adopted ASU 2014-09 on January 1, 2018 and did not identify any significant changes in the timing of revenue recognition when considering the amended accounting guidance. Additional disclosures related to revenue recognition appear in "Note 5. Revenue." In February 2016, the FASB issued ASU 2016-02, Leases
Fair Value Measurements	The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data.
Fair Value of Financial Instruments	The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument: • Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments. •

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	Original purchase price $ 27,420 Purchase price true-up 26 Historical carrying value of assets allocated to "Property, plant and equipment" 19,533 Excess purchase price over carrying value of acquired assets $ 7,913

Divestitures, Asset Impairmen28

Divestitures, Asset Impairments, and Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Disclosure of Long Lived Assets Held-for-sale	At June 30, 2018 and December 31, 2017, certain terminalling and storage and marine transportation assets met the criteria to be classified as held for sale in accordance with ASC 360-10 and are presented at the lower of the assets' carrying amount or fair value less cost to sell by segment in current assets as follows: June 30, 2018 December 31, 2017 Terminalling and storage $ 4,358 $ 4,152 Marine transportation 3,800 5,427 Assets held for sale $ 8,158 $ 9,579

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table disaggregates our revenue by major source: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Terminalling and storage segment Lubricant product sales $ 36,824 $ 33,413 $ 73,304 $ 65,560 Throughput and storage 24,090 24,695 48,154 49,353 $ 60,914 $ 58,108 $ 121,458 $ 114,913 Natural gas services segment Natural gas liquids product sales $ 90,643 $ 73,666 $ 249,806 $ 200,323 Natural gas storage 13,804 14,838 29,160 29,503 $ 104,447 $ 88,504 $ 278,966 $ 229,826 Sulfur service segment Sulfur product sales $ 10,479 $ 11,193 $ 22,316 $ 24,273 Fertilizer product sales 25,205 20,834 48,268 47,281 Sulfur services 2,787 2,850 5,574 5,700 $ 38,471 $ 34,877 $ 76,158 $ 77,254 Marine transportation segment Inland transportation $ 11,206 $ 11,022 $ 20,898 $ 22,313 Offshore transportation 1,533 1,411 3,295 2,941 $ 12,739 $ 12,433 $ 24,193 $ 25,254
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied at the end of the reporting period. The Partnership applies the practical expedient in ASC 606-10-50-14(a) and does not disclose information about remaining performance obligations that have original expected durations of one year or less. 2018 2019 2020 2021 2022 Thereafter Total Terminalling and storage Storage and throughput $ 25,119 $ 50,629 $ 49,330 $ 46,022 $ 41,505 $ 393,700 $ 606,305 Natural gas services Natural gas storage $ 19,141 $ 32,703 $ 26,935 $ 25,134 $ 24,615 $ 10,107 $ 138,635 Sulfur services Sulfur product sales $ 8,398 $ 16,796 $ 4,898 $ 1,181 $ 295 $ — $ 31,568 Marine transportation Offshore transportation $ 3,128 $ 6,205 $ 6,069 $ — $ — $ — $ 15,402 Total $ 55,786 $ 106,333 $ 87,232 $ 72,337 $ 66,415 $ 403,807 $ 791,910

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2018
Inventory Disclosure [Abstract]
Components of Inventory	Components of inventories at June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 December 31, 2017 Natural gas liquids $ 60,176 $ 47,462 Sulfur 14,542 8,436 Sulfur based products 12,108 18,674 Lubricants 23,488 20,086 Other 2,786 2,594 $ 113,100 $ 97,252

Investment in West Texas LPG 31

Investment in West Texas LPG Pipeline L.P. (Tables)	6 Months Ended
	Jun. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Select Financial Information for Significant Unconsolidated Equity Method Investees	Selected financial information for WTLPG is as follows: As of June 30, Three Months Ended June 30, Six Months Ended June 30, Total Assets Long-Term Debt Members' Equity Revenues Net Income Revenues Net Income 2018 WTLPG $ 917,441 $ — $ 868,112 $ 23,390 $ 5,653 $ 46,431 $ 13,359 As of December 31, 2017 WTLPG $ 837,163 $ — $ 787,426 $ 21,420 $ 4,264 $ 41,139 $ 8,789

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	At June 30, 2018 and December 31, 2017 , long-term debt consisted of the following: June 30, December 31, $664,444 Revolving credit facility at variable interest rate (5.09% 1 weighted average at June 30, 2018), due March 2020 secured by substantially all of the Partnership’s assets, including, without limitation, inventory, accounts receivable, vessels, equipment, fixed assets and the interests in the Partnership’s operating subsidiaries and equity method investees, net of unamortized debt issuance costs of $4,879 and $4,986, respectively 2,3 $ 459,121 $ 440,014 $400,000 Senior notes, 7.25% interest, net of unamortized debt issuance costs of $1,796 and $2,138, respectively, including unamortized premium of $803 and $956, respectively, issued $250,000 February 2013 and $150,000 April 2014, $26,200 repurchased during 2015, due February 2021, unsecured 3,4 372,807 372,618 Total long-term debt, net $ 831,928 $ 812,632 1 Interest rate fluctuates based on the LIBOR rate plus an applicable margin set on the date of each advance. The margin above LIBOR is set every three months. Indebtedness under the credit facility bears interest at LIBOR plus an applicable margin or the base prime rate plus an applicable margin. All amounts outstanding at June 30, 2018 and December 31, 2017 were at LIBOR plus an applicable margin. The applicable margin for revolving loans that are LIBOR loans ranges from 2.00% to 3.00% and the applicable margin for revolving loans that are base prime rate loans ranges from 1.00% to 2.00% . The applicable margin for existing LIBOR borrowings at June 30, 2018 is 3.00% . The credit facility contains various covenants which limit the Partnership’s ability to make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management (the "Omnibus Agreement"). The Partnership is permitted to make quarterly distributions so long as no event of default exists. 2 On February 21, 2018, the Partnership amended its revolving credit facility to, among other things, (i) create an inventory financing sublimit tranche, which is a part of and not in addition to the already existing commitments under the revolving credit facility, under which availability is subject to a borrowing base calculated by reference to eligible petroleum products inventory, (ii) exclude the amount of loans under the inventory financing sublimit tranche from total outstanding indebtedness for purposes of determining leverage ratio covenants under the revolving credit facility, (iii) increase the maximum permitted leverage ratio (as defined in the credit agreement, being generally computed as the ratio of total funded debt to consolidated earnings before interest, taxes, depreciation, amortization and certain other non-cash charges) from 5.25 to 1.00 , with a temporary springing provision to 5.50 to 1.00 under certain scenarios, to 5.75 to 1.00 for the first and second quarters of 2018, 5.50 to 1.00 for the next three quarters and 5.25 to 1.00 , with the temporary springing provision to 5.50 to 1.00 going back into effect, thereafter and (iv) decrease the maximum permitted senior leverage ratio (as defined in the credit agreement, being generally computed as the ratio of total secured funded debt to consolidated earnings before interest, taxes, depreciation, amortization and certain other non-cash charges) from 3.50 to 1.00 to 3.25 to 1.00 . The maximum amount of the inventory financing sublimit tranche is $10,000 during the period between March 1 and June 30 of each year, and $75,000 at all other times during each year. 3 The Partnership is in compliance with all debt covenants as of June 30, 2018 and December 31, 2017 , respectively. 4 The 2021 indenture restricts the Partnership’s ability to sell assets; pay distributions or repurchase units or redeem or repurchase subordinated debt; make investments; incur or guarantee additional indebtedness or issue preferred units; and consolidate, merge or transfer all or substantially all of its assets.

Supplemental Balance Sheet In33

Supplemental Balance Sheet Information (Tables)	6 Months Ended
	Jun. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Schedule of Other Assets	Components of "Other assets, net" were as follows: June 30, 2018 December 31, 2017 Customer contracts and relationships, net $ 21,730 $ 25,252 Other intangible assets 1,506 1,752 Other 4,966 5,797 $ 28,202 $ 32,801
Schedule of Other Accrued Liabilities	Components of "Other accrued liabilities" were as follows: June 30, 2018 December 31, 2017 Accrued interest $ 11,985 $ 11,726 Asset retirement obligations 3,374 5,429 Property and other taxes payable 5,310 5,638 Accrued payroll 2,419 3,385 Other 5 162 $ 23,093 $ 26,340
Schedule of Asset Retirement Obligations	The schedule below summarizes the changes in our asset retirement obligations: June 30, 2018 Beginning asset retirement obligations $ 13,512 Revisions to existing liabilities 1 4,756 Accretion expense 261 Liabilities settled (4,670 ) Ending asset retirement obligations 13,859 Current portion of asset retirement obligations 2 (3,374 ) Long-term portion of asset retirement obligations 3 $ 10,485 1 Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining useful life of the assets. The 2018 revisions reflect changes in removal cost estimates and the estimated remaining useful life of assets. 2 The current portion of asset retirement obligations is included in "Other current liabilities" on the Partnership's Consolidated and Condensed Balance Sheets. 3

Derivative Instruments and He34

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Effect of Derivative Instruments on the Consolidated Balance Sheets	The following table summarizes the fair value and classification of the Partnership’s derivative instruments in its Consolidated and Condensed Balance Sheets: Fair Values of Derivative Instruments in the Consolidated and Condensed Balance Sheets Derivative Assets Derivative Liabilities Fair Values Fair Values Balance Sheet Location June 30, 2018 December 31, 2017 Balance Sheet Location June 30, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Current: Commodity contracts Fair value of derivatives $ — $ — Fair value of derivatives $ 572 $ 72 Total derivatives not designated as hedging instruments $ — $ — $ 572 $ 72
Effect of Derivative Instruments on the Consolidated Statement of Operations	Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Three Months Ended June 30, 2018 and 2017 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2018 2017 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ (401 ) $ 103 Total effect of derivatives not designated as hedging instruments $ (401 ) $ 103 Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Six Months Ended June 30, 2018 and 2017 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2018 2017 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ 2,069 $ (2,392 ) Total effect of derivatives not designated as hedging instruments $ 2,069 $ (2,392 )

Partners' Capital (Tables)

Partners' Capital (Tables)	6 Months Ended
	Jun. 30, 2018
Partners' Capital Notes [Abstract]
Reconciliation of Net Income to Partners Interest in Net Income	The following is a reconciliation of net income allocated to the general partner and limited partners for purposes of calculating net income attributable to limited partners per unit: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net income (loss) $ (7,246 ) $ 989 $ 5,572 $ 14,572 Less general partner’s interest in net income (loss): Distributions payable on behalf of IDRs — — — — Distributions payable on behalf of general partner interest 392 393 784 785 General partner interest in undistributed loss (537 ) (374 ) (673 ) (494 ) Less income (loss) allocable to unvested restricted units (6 ) 3 2 38 Limited partners’ interest in net income (loss) $ (7,095 ) $ 967 $ 5,459 $ 14,243 The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Basic weighted average limited partner units outstanding 38,722,037 38,357,293 38,828,845 37,842,140 Dilutive effect of restricted units issued — 56,618 5,576 52,476 Total weighted average limited partner diluted units outstanding 38,722,037 38,413,911 38,834,421 37,894,616

Unit Based Awards (Tables)

Unit Based Awards (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Compensation Costs Related to Unit Based Plan	Amounts recognized in selling, general, and administrative expense in the consolidated and condensed financial statements with respect to these plans are as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Employees $ 345 $ 182 $ 441 $ 341 Non-employee directors 43 37 79 64 Total unit-based compensation expense $ 388 $ 219 $ 520 $ 405
Summary of Restricted Unit Activity	A summary of the restricted unit activity for the six months ended June 30, 2018 is provided below: Number of Units Weighted Average Grant-Date Fair Value Per Unit Non-vested, beginning of period 98,750 $ 24.80 Granted (TBRU) 315,500 $ 13.89 Granted (PBRU) 317,925 $ 13.89 Vested (80,550 ) $ 27.71 Forfeited (7,000 ) $ 13.90 Non-Vested, end of period 644,625 $ 13.91 Aggregate intrinsic value, end of period $ 8,896
Summary of Aggregate Intrinsic Value and Fair Value of Units Vested	A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the six months ended June 30, 2018 and 2017 is provided below: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Aggregate intrinsic value of units vested $ — $ 10 $ 1,188 $ 135 Fair value of units vested — 20 2,232 190

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2018
Related Party Transactions [Abstract]
The Impact of Related Party Transactions	The impact of related party revenues from sales of products and services is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Revenues: Terminalling and storage $ 20,507 $ 20,331 $ 40,532 $ 40,035 Marine transportation 4,105 4,187 7,718 8,512 Natural gas services — 6 — 118 Product sales: Natural gas services 18 — 19 942 Sulfur services 226 587 612 1,018 Terminalling and storage 182 137 437 194 426 724 1,068 2,154 $ 25,038 $ 25,248 $ 49,318 $ 50,819 The impact of related party cost of products sold is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Cost of products sold: Natural gas services $ 3,099 $ 2,909 $ 7,417 $ 11,803 Sulfur services 4,345 3,767 8,871 7,442 Terminalling and storage 8,009 4,119 14,567 9,186 $ 15,453 $ 10,795 $ 30,855 $ 28,431 The impact of related party operating expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Operating expenses: Marine transportation $ 6,000 $ 6,067 $ 11,321 $ 12,063 Natural gas services 2,232 2,233 4,431 4,468 Sulfur services 1,492 1,534 2,831 2,980 Terminalling and storage 4,615 6,618 9,140 13,317 $ 14,339 $ 16,452 $ 27,723 $ 32,828 The impact of related party selling, general and administrative expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Selling, general and administrative: Marine transportation $ 7 $ 7 $ 15 $ 15 Natural gas services 1,025 1,202 3,279 3,479 Sulfur services 660 621 1,319 1,257 Terminalling and storage 690 566 1,371 1,109 Indirect, including overhead allocation 4,116 4,104 8,235 8,208 $ 6,498 $ 6,500 $ 14,219 $ 14,068

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Segment Reporting by Segment	Three Months Ended June 30, 2018 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 62,314 $ (1,400 ) $ 60,914 $ 11,690 $ 1,739 $ 2,471 Natural gas services 104,447 — 104,447 5,304 3,727 2,043 Sulfur services 38,471 — 38,471 2,086 3,048 966 Marine transportation 13,168 (429 ) 12,739 1,811 1,353 2,827 Indirect selling, general and administrative — — — — (4,346 ) — Total $ 218,400 $ (1,829 ) $ 216,571 $ 20,891 $ 5,521 $ 8,307 Three Months Ended June 30, 2017 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 59,561 $ (1,453 ) $ 58,108 $ 10,327 $ 3,252 $ 8,634 Natural gas services 88,504 — 88,504 6,205 4,424 4,383 Sulfur services 34,877 — 34,877 2,030 6,295 862 Marine transportation 13,144 (711 ) 12,433 1,764 1,149 1 Indirect selling, general and administrative — — — — (4,272 ) — Total $ 196,086 $ (2,164 ) $ 193,922 $ 20,326 $ 10,848 $ 13,880 Six Months Ended June 30, 2018 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 124,297 $ (2,839 ) $ 121,458 $ 21,849 $ 4,461 $ 4,592 Natural gas services 278,966 — 278,966 10,605 21,138 3,052 Sulfur services 76,158 — 76,158 4,150 10,040 2,514 Marine transportation 25,196 (1,003 ) 24,193 3,497 2,516 11,118 Indirect selling, general and administrative — — — — (8,577 ) — Total $ 504,617 $ (3,842 ) $ 500,775 $ 40,101 $ 29,578 $ 21,276 Six Months Ended June 30, 2017 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 118,139 $ (3,226 ) $ 114,913 $ 25,804 $ 1,151 $ 16,097 Natural gas services 229,826 — 229,826 12,366 22,697 5,235 Sulfur services 77,254 — 77,254 4,063 17,062 1,167 Marine transportation 26,558 (1,304 ) 25,254 3,429 2,378 695 Indirect selling, general and administrative — — — — (8,692 ) — Total $ 451,777 $ (4,530 ) $ 447,247 $ 45,662 $ 34,596 $ 23,194
Assets by Segment	The Partnership's assets by reportable segment as of June 30, 2018 and December 31, 2017 , are as follows: June 30, 2018 December 31, 2017 Total assets: Terminalling and storage $ 319,619 $ 326,920 Natural gas services 669,531 704,524 Sulfur services 121,452 120,790 Marine transportation 108,163 101,264 Total assets $ 1,218,765 $ 1,253,498

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	June 30, 2018 December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value 2021 Senior unsecured notes $ 372,807 $ 370,245 $ 372,618 $ 381,657 Level 2 June 30, 2018 December 31, 2017 Commodity derivative contracts, net $ (572 ) $ (72 )

Nature of Operations and Basi40

Nature of Operations and Basis of Presentation (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)segment	Jun. 30, 2017USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of primary business lines | segment				4
Operating expenses	[1]	$ 31,510	$ 32,552	$ 62,964	$ 65,926
Cost of products sold		$ 149,587	121,302	$ 349,400	282,093
Reclassification of certain Terminalling and Storage product expenses | Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating expenses			34,435		69,492
Cost of products sold			$ 119,419		$ 278,527
[1]	Related Party Transactions Included Above Three Months Ended Six Months Ended June 30, June 30, 2018 2017 2018 2017 Revenues:* Terminalling and storage $ 20,507 $ 20,331 $ 40,532 $ 40,035 Marine transportation 4,105 4,187 7,718 8,512 Natural gas services — 6 — 118 Product Sales 426 724 1,068 2,154 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Natural gas services 3,099 2,909 7,417 11,803 Sulfur services 4,345 3,767 8,871 7,442 Terminalling and storage 8,009 4,119 14,567 9,186 Expenses: Operating expenses 14,339 16,452 27,723 32,828 Selling, general and administrative 6,498 6,500 14,219 14,068

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	Feb. 22, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Excess purchase price over carrying value of acquired assets		$ 26	$ 7,887
MEH South Texas Terminals LLC
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Purchase price	$ 27,420	27,420
Excess purchase price over carrying value of acquired assets	$ 7,887	7,913
Purchase price true-up		$ 26
Excess purchase price over carrying value of acquired assets, percentage	3.00%

Acquisitions - Purchase Price (

Acquisitions - Purchase Price (Details) - USD ($) $ in Thousands	Feb. 22, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Excess purchase price over carrying value of acquired assets		$ 26	$ 7,887
MEH South Texas Terminals LLC
Business Acquisition [Line Items]
Original purchase price	$ 27,420	27,420
Purchase price true-up		26
Historical carrying value of assets allocated to Property, plant and equipment		19,533
Excess purchase price over carrying value of acquired assets	$ 7,887	$ 7,913

Divestitures, Asset Impairmen43

Divestitures, Asset Impairments, and Discontinued Operations - (Long-Lived Assets Held-for-Sale) (Details) - Disposal Group, Held-for-sale, Not Discontinued Operations - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 8,158	$ 9,579
Terminalling and storage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	4,358	4,152
Marine transportation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 3,800	$ 5,427

Revenue - Dissagregation of Rev

Revenue - Dissagregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Terminalling and storage segment
Disaggregation of Revenue [Line Items]
Revenue	$ 60,914	$ 58,108	$ 121,458	$ 114,913
Terminalling and storage segment | Lubricant product sales
Disaggregation of Revenue [Line Items]
Revenue	36,824	33,413	73,304	65,560
Terminalling and storage segment | Throughput and storage
Disaggregation of Revenue [Line Items]
Revenue	24,090	24,695	48,154	49,353
Natural gas services segment
Disaggregation of Revenue [Line Items]
Revenue	104,447	88,504	278,966	229,826
Natural gas services segment | Natural gas liquids product sales
Disaggregation of Revenue [Line Items]
Revenue	90,643	73,666	249,806	200,323
Natural gas services segment | Natural gas storage
Disaggregation of Revenue [Line Items]
Revenue	13,804	14,838	29,160	29,503
Sulfur service segment
Disaggregation of Revenue [Line Items]
Revenue	38,471	34,877	76,158	77,254
Sulfur service segment | Sulfur product sales
Disaggregation of Revenue [Line Items]
Revenue	10,479	11,193	22,316	24,273
Sulfur service segment | Fertilizer product sales
Disaggregation of Revenue [Line Items]
Revenue	25,205	20,834	48,268	47,281
Sulfur service segment | Sulfur services
Disaggregation of Revenue [Line Items]
Revenue	2,787	2,850	5,574	5,700
Marine transportation segment
Disaggregation of Revenue [Line Items]
Revenue	12,739	12,433	24,193	25,254
Marine transportation segment | Inland transportation
Disaggregation of Revenue [Line Items]
Revenue	11,206	11,022	20,898	22,313
Marine transportation segment | Offshore transportation
Disaggregation of Revenue [Line Items]
Revenue	$ 1,533	$ 1,411	$ 3,295	$ 2,941

Revenue - Estimated Revenue Exp

Revenue - Estimated Revenue Expected to be Recognized in Future (Details) $ in Thousands	Jun. 30, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 55,786
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 25,119
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 19,141
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 8,398
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 3,128
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 106,333
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 50,629
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 32,703
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 16,796
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 6,205
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 87,232
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 49,330
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 26,935
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 4,898
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 6,069
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 72,337
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 46,022
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 25,134
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 1,181
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 66,415
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 41,505
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 24,615
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 295
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 403,807
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 393,700
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 10,107
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 791,910
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Throughput and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	606,305
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Natural gas storage | Natural gas services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	138,635
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Sulfur product sales | Sulfur services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	31,568
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Offshore transportation | Marine transportation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 15,402

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Natural gas liquids	$ 60,176	$ 47,462
Sulfur	14,542	8,436
Sulfur based products	12,108	18,674
Lubricants	23,488	20,086
Other	2,786	2,594
Inventories	$ 113,100	$ 97,252

Investment in West Texas LPG 47

Investment in West Texas LPG Pipeline L.P. - Narrative (Details) - West Texas LPG Pipeline L.P.	Jun. 30, 2018mi
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
Length of common-carrier pipeline system (in miles)	2,300
Common Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	19.80%
General Partner
Schedule of Equity Method Investments [Line Items]
Ownership percentage	0.20%

Investment in West Texas LPG 48

Investment in West Texas LPG Pipeline L.P. - Selected Financial Information for Equity Method Investees (Details) - West Texas LPG Pipeline L.P. - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Total Assets	$ 917,441		$ 917,441		$ 837,163
Long-Term Debt	0		0		0
Members' Equity	868,112		868,112		$ 787,426
Revenues	23,390	$ 21,420	46,431	$ 41,139
Net Income	$ 5,653	$ 4,264	$ 13,359	$ 8,789

Long-Term Debt (Details)

Long-Term Debt (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Feb. 21, 2018USD ($)	Feb. 20, 2018	Dec. 31, 2017USD ($)	Dec. 31, 2015USD ($)	Apr. 30, 2014USD ($)	Feb. 28, 2013USD ($)
Debt Instrument [Line Items]
Total long-term debt, net	$ 831,928,000		$ 831,928,000				$ 812,632,000
Cash paid for interest	6,077,000	$ 4,328,000	24,955,000	$ 22,509,000
Capitalized interest	167,000	$ 222,000	328,000	$ 445,000
Revolving Loan Facility
Debt Instrument [Line Items]
Total long-term debt, net	459,121,000		459,121,000				440,014,000
Face amount	$ 664,444,000		$ 664,444,000
Weighted average interest rate	5.09%		5.09%
Unamortized debt issuance costs	$ 4,879,000		$ 4,879,000				4,986,000
Debt instrument, covenant, leverage ratio, maximum						5.25
Debt instrument, covenant, leverage ratio with temporary springing provision, maximum						5.50
Debt instrument, covenant, senior leverage ratio, maximum					3.25	3.50
Revolving Loan Facility | LIBOR
Debt Instrument [Line Items]
Applicable margins			3.00%
Revolving Loan Facility | LIBOR | Minimum
Debt Instrument [Line Items]
Applicable margins			2.00%
Revolving Loan Facility | LIBOR | Maximum
Debt Instrument [Line Items]
Applicable margins			3.00%
Revolving Loan Facility | Prime Rate | Minimum
Debt Instrument [Line Items]
Applicable margins			1.00%
Revolving Loan Facility | Prime Rate | Maximum
Debt Instrument [Line Items]
Applicable margins			2.00%
Revolving Loan Facility | January 1, 2018 to June 30, 2018
Debt Instrument [Line Items]
Debt instrument, covenant, leverage ratio, maximum					5.75
Revolving Loan Facility | July 1, 2018 to March 31, 2019
Debt Instrument [Line Items]
Debt instrument, covenant, leverage ratio, maximum					5.50
Revolving Loan Facility | Subsequent to March 31, 2019
Debt Instrument [Line Items]
Debt instrument, covenant, leverage ratio, maximum					5.25
Debt instrument, covenant, leverage ratio with temporary springing provision, maximum					5.50
Revolving Loan Facility | March 1 to June 30 of each year
Debt Instrument [Line Items]
Debt instrument, covenant, inventory financing sublimit tranche, maximum					$ 10,000,000
Revolving Loan Facility | Periods excluding March 1 to June 30 of each year
Debt Instrument [Line Items]
Debt instrument, covenant, inventory financing sublimit tranche, maximum					$ 75,000,000
Senior Notes | Senior Notes 7.25%
Debt Instrument [Line Items]
Total long-term debt, net	372,807,000		$ 372,807,000				372,618,000
Face amount	400,000,000		400,000,000						$ 150,000,000	$ 250,000,000
Unamortized debt issuance costs	$ 1,796,000		$ 1,796,000				2,138,000
Stated interest rate	7.25%		7.25%
Unamortized premium	$ 803,000		$ 803,000				$ 956,000
Repurchase amount								$ 26,200,000

Supplemental Balance Sheet In50

Supplemental Balance Sheet Information - Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Customer contracts and relationships, net	$ 21,730	$ 25,252
Other intangible assets	1,506	1,752
Other	4,966	5,797
Other assets, net	28,202	32,801
Accumulated amortization of intangible assets	$ 44,425	$ 39,462

Supplemental Balance Sheet In51

Supplemental Balance Sheet Information - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Accrued interest	$ 11,985	$ 11,726
Asset retirement obligations	3,374	5,429
Property and other taxes payable	5,310	5,638
Accrued payroll	2,419	3,385
Other	5	162
Total other accrued liabilities	$ 23,093	$ 26,340

Supplemental Balance Sheet In52

Supplemental Balance Sheet Information - Asset Retirement Obligations (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning asset retirement obligations	$ 13,512
Revisions to existing liabilities	4,756
Accretion expense	261
Liabilities settled	(4,670)
Ending asset retirement obligations	13,859
Current portion of asset retirement obligations	(3,374)	$ (5,429)
Long-term portion of asset retirement obligations	$ 10,485

Derivative Instruments and He53

Derivative Instruments and Hedging Activities - Narrative (Details) - bbl	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Commodity contracts
Derivatives, Fair Value [Line Items]
Notional quantity (in bbl)	360	145

Derivative Instruments and He54

Derivative Instruments and Hedging Activities - Balance Sheet Derivatives (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 0	$ 0
Derivative Liabilities	572	72
Commodity contracts | Fair value of derivatives
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	$ 572	$ 72

Derivative Instruments and He55

Derivative Instruments and Hedging Activities - Statement of Operations Derivatives (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (401)	$ 103	$ 2,069	$ (2,392)
Commodity contracts | Cost of products sold
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (401)	$ 103	$ 2,069	$ (2,392)

Partners' Capital - Narrative (

Partners' Capital - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 22, 2017	Jun. 30, 2018	Jun. 30, 2017
Limited Partners' Capital Account [Line Items]
Common limited partner units (in shares)		39,052,237
Ownership percentage		98.00%
General partner interest percentage		2.00%
Common units sold in public offering (in shares)	2,990,000
Share price (USD per share)	$ 18
Proceeds from the sale of common units, net of offering costs	$ 51,071
General partner contribution	$ 1,098	$ 0	$ 1,098
Martin Resource Management
Limited Partners' Capital Account [Line Items]
Voting interest percentage		51.00%
Martin Resource Management
Limited Partners' Capital Account [Line Items]
Common limited partner units (in shares)		6,114,532
Ownership percentage		15.70%
General partner interest percentage		2.00%
Voting interest percentage		15.70%

Partners' Capital - Incentive D

Partners' Capital - Incentive Distribution Rights and Distributions of Available Cash (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Limited Partners' Capital Account [Line Items]
General partner interest percentage			2.00%
Incentive distribution	$ 0	$ 0	$ 0	$ 0
Distribution period			45 days
Martin Midstream GP LLC
Limited Partners' Capital Account [Line Items]
General partner interest percentage			2.00%
Incentive distribution	$ 0	$ 0	$ 0	$ 0
Martin Midstream GP LLC | Target Level 1
Limited Partners' Capital Account [Line Items]
Target cash distribution, percent	2.00%		2.00%
Target cash distribution (USD per share)	$ 0.55		$ 0.55
Martin Midstream GP LLC | Target Level 2
Limited Partners' Capital Account [Line Items]
Target cash distribution, percent	15.00%		15.00%
Target cash distribution (USD per share)	$ 0.625		$ 0.625
Martin Midstream GP LLC | Target Level 3
Limited Partners' Capital Account [Line Items]
Target cash distribution, percent	25.00%		25.00%
Target cash distribution (USD per share)	$ 0.75		$ 0.75
Martin Midstream GP LLC | Target Level 4
Limited Partners' Capital Account [Line Items]
Target cash distribution, percent	50.00%		50.00%
Minimum | Martin Midstream GP LLC | Target Level 1
Limited Partners' Capital Account [Line Items]
Target cash distribution (USD per share)	$ 0.50		$ 0.50
Maximum | Martin Midstream GP LLC | Target Level 1
Limited Partners' Capital Account [Line Items]
Target cash distribution (USD per share)	$ 0.55		$ 0.55

Partners' Capital - Net Income

Partners' Capital - Net Income Per Unit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Partners' Capital Notes [Abstract]
Net income (loss)	$ (7,246)	$ 989	$ 5,572	$ 14,572
Less general partner’s interest in net income (loss):
Distributions payable on behalf of IDRs	0	0	0	0
Distributions payable on behalf of general partner interest	392	393	784	785
General partner interest in undistributed loss	(537)	(374)	(673)	(494)
Less income (loss) allocable to unvested restricted units	(6)	3	2	38
Limited partners’ interest in net income (loss)	$ (7,095)	$ 967	$ 5,459	$ 14,243
Basic weighted average limited partner units outstanding (in shares)	38,722,037	38,357,293	38,828,845	37,842,140
Dilutive effect of restricted units issued (in shares)	0	56,618	5,576	52,476
Total weighted average limited partner diluted units outstanding (in shares)	38,722,037	38,413,911	38,834,421	37,894,616

Unit Based Awards - Schedule of

Unit Based Awards - Schedule of Compensation Costs (Details) - Selling, General and Administrative Expenses - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 388	$ 219	$ 520	$ 405
Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	345	182	441	341
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 43	$ 37	$ 79	$ 64

Unit Based Awards - Narrative (

Unit Based Awards - Narrative (Details) $ in Thousands	Jan. 24, 2022shares	Jan. 24, 2021shares	Jan. 24, 2020shares	Jan. 24, 2019shares	Mar. 01, 2018shares	Feb. 20, 2018directorshares	Jun. 30, 2018USD ($)shares	May 26, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)								3,000,000
Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of units (in shares)							80,550
Unrecognized compensation cost related to non-vested restricted units | $							$ 4,052
Weighted average period for recognition (in years)							2 years 10 months 2 days
Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)							3 years
Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)							4 years
Time Based Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)							3 years
Granted, number of units (in shares)							315,500
Number of independent directors receiving grants | director						3
Time Based Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)					301,550
Time Based Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)						4,650
Performance Based Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)							3 years
Granted, number of units (in shares)							317,925
Performance Based Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)					317,925
Scenario, Forecast | Time Based Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of units (in shares)	1,162.5	1,162.5	1,162.5	1,162.5

Unit Based Awards - Restricted

Unit Based Awards - Restricted Unit Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)$ / sharesshares
Restricted Units
Number of Units
Non-vested, beginning of period, number of units (in shares) | shares	98,750
Vested, number of units (in shares) | shares	(80,550)
Forfeited, number of units (in shares) | shares	(7,000)
Non-vested, end of period, number of units (in shares) | shares	644,625
Weighted Average Grant-Date Fair Value Per Unit
Non-vested, beginning of period, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 24.80
Vested, weighted average grant-date fair value per unit (USD per share) | $ / shares	27.71
Forfeited, weighted average grant-date fair value per unit (USD per share) | $ / shares	13.90
Non-vested, end of period, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 13.91
Aggregate intrinsic value, end of period | $	$ 8,896
Time Based Restricted Units
Number of Units
Granted, number of units (in shares) | shares	315,500
Weighted Average Grant-Date Fair Value Per Unit
Granted, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 13.89
Performance Based Restricted Units
Number of Units
Granted, number of units (in shares) | shares	317,925
Weighted Average Grant-Date Fair Value Per Unit
Granted, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 13.89

Unit Based Awards - Intrinsic a

Unit Based Awards - Intrinsic and Fair Value (Details) - Restricted Units - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of units vested	$ 0	$ 10	$ 1,188	$ 135
Fair value of units vested	$ 0	$ 20	$ 2,232	$ 190

Related Party Transactions - Na

Related Party Transactions - Narrative (Details)	6 Months Ended
	Jun. 30, 2018shares
Related Party Transaction [Line Items]
General partner interest percentage	2.00%
Martin Resource Management
Related Party Transaction [Line Items]
Number of shares owned (in shares)	6,114,532
Ownership percentage	15.70%
General partner interest percentage	2.00%
MMGP Holdings, LLC | Martin Resource Management
Related Party Transaction [Line Items]
General partner interest percentage	51.00%

Related Party Transactions - Om

Related Party Transactions - Omnibus Agreement (Details) - Omnibus Agreement - Martin Resource Management - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Related Party Transaction [Line Items]
Noncompete restriction threshold	$ 5,000,000		$ 5,000,000
Noncompete restriction ownership option opportunity threshold minimum	5,000,000		5,000,000
Noncompete restriction ownership option opportunity threshold minimum with equity limitation	$ 5,000,000		$ 5,000,000
Equity limitation on ownership restriction percentage	20.00%		20.00%
Approved annual reimbursements for indirect expenses	$ 16,416,000		$ 16,416,000
Indirect expenses reimbursed	$ 4,104,000	$ 4,104,000	$ 8,208,000	$ 8,208,000

Related Party Transactions - Mo

Related Party Transactions - Motor Carrier Agreement (Details) - Motor Carrier Agreement - Martin Resource Management	6 Months Ended
	Jun. 30, 2018
Related Party Transaction [Line Items]
Automatic consecutive term renewal period (in years)	1 year
Termination written notice, minimum (in days)	30 days
Partnership notice period to terminate agreement (in days)	90 days

Related Party Transactions - Ma

Related Party Transactions - Marine Agreements (Details) - Marine Transportation Agreement - Martin Resource Management	6 Months Ended
	Jun. 30, 2018
Related Party Transaction [Line Items]
Automatic consecutive term renewal period (in years)	1 year
Termination written notice, minimum (in days)	60 days

Related Party Transactions - Te

Related Party Transactions - Terminal Services Agreements (Details)	6 Months Ended
	Jun. 30, 2018
Martin Resource Management
Related Party Transaction [Line Items]
Termination written notice, minimum (in days)	60 days

Related Party Transactions - Ot

Related Party Transactions - Other Agreements (Details) - Martin Resource Management	6 Months Ended
	Jun. 30, 2018bbl
Cross Tolling Agreement
Related Party Transaction [Line Items]
Production minimum per day (in bbl)	6,500
Annual escalation benchmark percentage	3.00%
Sulfuric Acid Sales Agency Agreement
Related Party Transaction [Line Items]
Partnership notice period to terminate agreement (in days)	90 days

Related Party Transactions - Sc

Related Party Transactions - Schedule of the Impact of Related Party Transactions (Details) - Related Party - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenue from related parties	$ 25,038	$ 25,248	$ 49,318	$ 50,819
Cost of products sold:
Cost of products sold	15,453	10,795	30,855	28,431
Operating expenses:
Operating expenses	14,339	16,452	27,723	32,828
Selling, general and administrative:
Selling, general and administrative	6,498	6,500	14,219	14,068
Terminalling and storage
Operating expenses:
Operating expenses	4,615	6,618	9,140	13,317
Marine transportation
Operating expenses:
Operating expenses	6,000	6,067	11,321	12,063
Natural gas services
Operating expenses:
Operating expenses	2,232	2,233	4,431	4,468
Sulfur services
Operating expenses:
Operating expenses	1,492	1,534	2,831	2,980
Operating segments | Terminalling and storage
Selling, general and administrative:
Selling, general and administrative	690	566	1,371	1,109
Operating segments | Marine transportation
Selling, general and administrative:
Selling, general and administrative	7	7	15	15
Operating segments | Natural gas services
Selling, general and administrative:
Selling, general and administrative	1,025	1,202	3,279	3,479
Operating segments | Sulfur services
Selling, general and administrative:
Selling, general and administrative	660	621	1,319	1,257
Indirect, including overhead allocation
Selling, general and administrative:
Selling, general and administrative	4,116	4,104	8,235	8,208
Terminalling and storage | Terminalling and storage
Revenues:
Revenue from related parties	20,507	20,331	40,532	40,035
Marine transportation | Marine transportation
Revenues:
Revenue from related parties	4,105	4,187	7,718	8,512
Natural gas services | Natural gas services
Revenues:
Revenue from related parties	0	6	0	118
Product sales
Revenues:
Revenue from related parties	426	724	1,068	2,154
Natural gas services | Natural gas services
Revenues:
Revenue from related parties	18	0	19	942
Cost of products sold:
Cost of products sold	3,099	2,909	7,417	11,803
Sulfur services | Sulfur services
Revenues:
Revenue from related parties	226	587	612	1,018
Cost of products sold:
Cost of products sold	4,345	3,767	8,871	7,442
Terminalling and storage | Terminalling and storage
Revenues:
Revenue from related parties	182	137	437	194
Cost of products sold:
Cost of products sold	$ 8,009	$ 4,119	$ 14,567	$ 9,186

Related Party Transactions - 70

Related Party Transactions - Other Related Party Transactions (Details) - Martin Energy Trading LLC - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Related Party Transaction [Line Items]
Due from related parties, annual interest rate			15.00%
Interest expense
Related Party Transaction [Line Items]
Interest income, related party	$ 0	$ 388	$ 0	$ 943
Notes Receivable
Related Party Transaction [Line Items]
Note receivable - affiliate	$ 15,000		$ 15,000

Business Segments (Details)

Business Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)segment	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			4
Segment Reporting Information [Line Items]
Total revenue	$ 216,571	$ 193,922	$ 500,775	$ 447,247
Depreciation and amortization	20,891	20,326	40,101	45,662
Operating Income (Loss) after Eliminations	5,521	10,848	29,578	34,596
Capital Expenditures and Plant Turnaround Costs	8,307	13,880	21,276	23,194
Total assets:
Total assets	1,218,765		1,218,765		$ 1,253,498
Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	60,914	58,108	121,458	114,913
Depreciation and amortization	11,690	10,327	21,849	25,804
Operating Income (Loss) after Eliminations	1,739	3,252	4,461	1,151
Capital Expenditures and Plant Turnaround Costs	2,471	8,634	4,592	16,097
Total assets:
Total assets	319,619		319,619		326,920
Natural gas services
Segment Reporting Information [Line Items]
Total revenue	104,447	88,504	278,966	229,826
Depreciation and amortization	5,304	6,205	10,605	12,366
Operating Income (Loss) after Eliminations	3,727	4,424	21,138	22,697
Capital Expenditures and Plant Turnaround Costs	2,043	4,383	3,052	5,235
Total assets:
Total assets	669,531		669,531		704,524
Sulfur services
Segment Reporting Information [Line Items]
Total revenue	38,471	34,877	76,158	77,254
Depreciation and amortization	2,086	2,030	4,150	4,063
Operating Income (Loss) after Eliminations	3,048	6,295	10,040	17,062
Capital Expenditures and Plant Turnaround Costs	966	862	2,514	1,167
Total assets:
Total assets	121,452		121,452		120,790
Marine transportation
Segment Reporting Information [Line Items]
Total revenue	12,739	12,433	24,193	25,254
Depreciation and amortization	1,811	1,764	3,497	3,429
Operating Income (Loss) after Eliminations	1,353	1,149	2,516	2,378
Capital Expenditures and Plant Turnaround Costs	2,827	1	11,118	695
Total assets:
Total assets	108,163		108,163		$ 101,264
Operating Revenues
Segment Reporting Information [Line Items]
Total revenue	218,400	196,086	504,617	451,777
Operating Revenues | Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	62,314	59,561	124,297	118,139
Operating Revenues | Natural gas services
Segment Reporting Information [Line Items]
Total revenue	104,447	88,504	278,966	229,826
Operating Revenues | Sulfur services
Segment Reporting Information [Line Items]
Total revenue	38,471	34,877	76,158	77,254
Operating Revenues | Marine transportation
Segment Reporting Information [Line Items]
Total revenue	13,168	13,144	25,196	26,558
Intersegment Revenues Eliminations
Segment Reporting Information [Line Items]
Total revenue	(1,829)	(2,164)	(3,842)	(4,530)
Intersegment Revenues Eliminations | Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	(1,400)	(1,453)	(2,839)	(3,226)
Intersegment Revenues Eliminations | Natural gas services
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Intersegment Revenues Eliminations | Sulfur services
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Intersegment Revenues Eliminations | Marine transportation
Segment Reporting Information [Line Items]
Total revenue	(429)	(711)	(1,003)	(1,304)
Indirect selling, general and administrative
Segment Reporting Information [Line Items]
Depreciation and amortization	0	0	0	0
Operating Income (Loss) after Eliminations	(4,346)	(4,272)	(8,577)	(8,692)
Capital Expenditures and Plant Turnaround Costs	$ 0	$ 0	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Oct. 02, 2012	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2018
Loss Contingencies [Line Items]
Non-cancelable revenue arrangements, future minimum revenues, 2018				$ 11,691
Non-cancelable revenue arrangements, future minimum revenues, 2019				19,315
Non-cancelable revenue arrangements, future minimum revenues, 2020				17,577
Non-cancelable revenue arrangements, future minimum revenues, 2021				15,681
Non-cancelable revenue arrangements, future minimum revenues, 2022				15,681
Non-cancelable revenue arrangements, future minimum revenues, subsequent years				$ 73,299
Martin Resource Management
Loss Contingencies [Line Items]
Quarterly purchase price reimbursement for non compliance	$ 750	$ 1,125
Maximum purchase price reimbursement for non compliance			$ 4,500

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Recurring | Level 2 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative contracts, net	$ (572)	$ (72)
Nonrecurring | 2021 Senior unsecured notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2021 Senior unsecured notes	372,807	372,618
Nonrecurring | 2021 Senior unsecured notes | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2021 Senior unsecured notes	$ 370,245	$ 381,657

Subsequent Events (Details)

Subsequent Events (Details) $ / shares in Units, $ in Thousands	Jul. 19, 2018$ / shares	Dec. 31, 2018USD ($)	Jun. 30, 2018	Feb. 21, 2018	Feb. 20, 2018
Revolving Loan Facility
Subsequent Event [Line Items]
Debt instrument, covenant, leverage ratio, maximum					5.25
Debt instrument, covenant, senior leverage ratio, maximum				3.25	3.50
WTLPG
Subsequent Event [Line Items]
Ownership percentage			20.00%
Subsequent Event
Subsequent Event [Line Items]
Dividends declared (USD per share) | $ / shares	$ 0.50
Estimated annualized dividends (USD per share) | $ / shares	$ 2
Subsequent Event | Scenario, Forecast | Revolving Loan Facility
Subsequent Event [Line Items]
Debt instrument, covenant, leverage ratio, maximum		5.25
Debt instrument, covenant, senior leverage ratio, maximum		3.50
Debt instrument, covenant, consolidated interest coverage ratio		2.50
Subsequent Event | WTLPG | Scenario, Forecast
Subsequent Event [Line Items]
Ownership percentage		20.00%
Proceeds from sale of equity method investments | $		$ 195,000
Proceeds from sale of equity method investments, net of transaction fees and expenses | $		$ 193,650